30,000 (thirty thousand) is the

natural number In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country"). Numbers used for counting are called ''cardinal ...

that comes after 29,999 and before 30,001.

Selected numbers in the range 30001–39999

30001 to 30999

* 30029 =

primorial prime In mathematics, a primorial prime is a prime number of the form ''pn''# ± 1, where ''pn''# is the primorial of ''pn'' (i.e. the product of the first ''n'' primes). Primality tests show that : ''pn''# − 1 is prime for ''n ...

* 30030 = primorial * 30031 = smallest

composite number A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Equivalently, it is a positive integer that has at least one divisor other than 1 and itself. Every positive integer is composite, prime, ...

which is one more than a primorial * 30203 =

safe prime In number theory, a prime number ''p'' is a if 2''p'' + 1 is also prime. The number 2''p'' + 1 associated with a Sophie Germain prime is called a . For example, 11 is a Sophie Germain prime and 2 × 11 + ...

* 30240 =

harmonic divisor number In mathematics, a harmonic divisor number, or Ore number (named after Øystein Ore who defined it in 1948), is a positive integer whose divisors have a harmonic mean that is an integer. The first few harmonic divisor numbers are: : 1, 6, 2 ...

* 30323 =

Sophie Germain prime In number theory, a prime number ''p'' is a if 2''p'' + 1 is also prime. The number 2''p'' + 1 associated with a Sophie Germain prime is called a . For example, 11 is a Sophie Germain prime and 2 × 11 + ...

and safe prime * 30420 = pentagonal pyramidal number * 30537 = Riordan number * 30694 =

open meandric number In mathematics, a meander or closed meander is a self-avoiding closed curve which intersects a line a number of times. Intuitively, a meander can be viewed as a road crossing a river through a number of bridges. Meander Given a fixed oriented li ...

* 30941 = first base 13 repunit prime

31000 to 31999

* 31116 =

octahedral number In number theory, an octahedral number is a figurate number that represents the number of spheres in an octahedron formed from close-packed spheres. The ''n''th octahedral number O_n can be obtained by the formula:. :O_n=. The first few octahed ...

* 31337 =

cousin prime In number theory, cousin primes are prime numbers that differ by four. Compare this with twin primes, pairs of prime numbers that differ by two, and sexy primes, pairs of prime numbers that differ by six. The cousin primes (sequences and in O ...

, pronounced ''elite'', an alternate way to spell '' 1337'', an obfuscated alphabet made with numbers and punctuation, known and used in the gamer,

hacker A hacker is a person skilled in information technology who uses their technical knowledge to achieve a goal or overcome an obstacle, within a computerized system by non-standard means. Though the term ''hacker'' has become associated in popu ...

, and

BBS BBS may refer to: Ammunition * BBs, BB gun metal bullets * BBs, airsoft gun plastic pellets Computing and gaming * Bulletin board system, a computer server users dial into via dial-up or telnet; precursor to the Internet * BIOS Boot Specificat ...

cultures. * 31395 = square pyramidal number * 31397 = prime number followed by a record

prime gap A prime gap is the difference between two successive prime numbers. The ''n''-th prime gap, denoted ''g'n'' or ''g''(''p'n'') is the difference between the (''n'' + 1)-th and the ''n''-th prime numbers, i.e. :g_n = p_ - p_n.\ W ...

of 72, the first greater than 52 * 31688 = the number of years approximately equal to 1 trillion seconds * 31721 = start of a

prime quadruplet In number theory, a prime quadruplet (sometimes called prime quadruple) is a set of four prime numbers of the form This represents the closest possible grouping of four primes larger than 3, and is the only prime constellation of length 4. Prim ...

* 31929 =

Zeisel number A Zeisel number, named after Helmut Zeisel, is a square-free integer ''k'' with at least three prime factors which fall into the pattern :p_x = ap_ + b where ''a'' and ''b'' are some integer constants and ''x'' is the index number of each prime f ...

32000 to 32999

* 32043 = smallest number whose

square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...

is pandigital. * 32045 = can be expressed as a sum of two squares in more ways than any smaller number. * 32760 = harmonic divisor number * 32761 = 181², centered hexagonal number * 32767 = 2¹⁵ − 1, largest positive value for a signed (

two's complement Two's complement is a mathematical operation to reversibly convert a positive binary number into a negative binary number with equivalent (but negative) value, using the binary digit with the greatest place value (the leftmost bit in big- endian ...

) 16-bit integer on a computer. * 32768 = 2¹⁵ = 8⁵, maximum absolute value of a negative value for a signed (two's complement) 16-bit integer on a computer. * 32800 = pentagonal pyramidal number * 32993 =

Leyland number In number theory, a Leyland number is a number of the form :x^y + y^x where ''x'' and ''y'' are integers greater than 1. They are named after the mathematician Paul Leyland. The first few Leyland numbers are : 8, 17, 32, 54, 57, 100, 145, 177, ...

33000 to 33999

* 33333 =

repdigit In recreational mathematics, a repdigit or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system (often implicitly decimal). The word is a portmanteau of repeated and digit. Example ...

* 33461 = Pell number, Markov number * 33511 = square pyramidal number * 33781 = octahedral number

34000 to 34999

* 34560 = 5 superfactorial * 34790 = number of non-isomorphic set-systems of weight 13. * 34841 = start of a prime quadruplet * 34969 = favorite number of the Muppet character

Count von Count Count von Count (known simply as the Count) is a Muppet character on the PBS/ HBO children's television show ''Sesame Street.'' He is meant to parody Bela Lugosi's portrayal of Count Dracula. He first appeared on the show in the Season 4 premie ...

35000 to 35999

* 35720 = square pyramidal number * 35840 = number of

ounce The ounce () is any of several different units of mass, weight or volume and is derived almost unchanged from the , an Ancient Roman unit of measurement. The avoirdupois ounce (exactly ) is avoirdupois pound; this is the United States customa ...

s in a long ton (2,240 pounds) * 35890 =

tribonacci number In mathematics, the Fibonacci numbers form a sequence defined recursively by: :F_n = \begin 0 & n = 0 \\ 1 & n = 1 \\ F_ + F_ & n > 1 \end That is, after two starting values, each number is the sum of the two preceding numbers. The Fibonacci seque ...

* 35899 = alternating factorial * 35937 = 33³, chiliagonal number * 35964 = digit-reassembly number

36000 to 36999

* 36100 = sum of the cubes of the first 19 positive integers * 36463 – number of parallelogram polyominoes with 14 cells * 36594 = octahedral number

37000 to 37999

* 37378 =

semi-meandric number In mathematics, a meander or closed meander is a self-avoiding closed curve which intersects a line a number of times. Intuitively, a meander can be viewed as a road crossing a river through a number of bridges. Meander Given a fixed oriented li ...

* 37634 = third term of the Lucas–Lehmer sequence * 37666 =

Markov number A Markov number or Markoff number is a positive integer ''x'', ''y'' or ''z'' that is part of a solution to the Markov Diophantine equation :x^2 + y^2 + z^2 = 3xyz,\, studied by . The first few Markov numbers are : 1, 2, 5, 13, 29, 34, 89 ...

* 37926 = pentagonal pyramidal number

38000 to 38999

* 38024 = square pyramidal number * 38209 = n such that n , (3ⁿ + 5) * 38416 = 14⁴ * 38807 = number of non-equivalent ways of expressing 10,000,000 as the sum of two prime numbers * 38962 =

Kaprekar number In mathematics, a natural number in a given number base is a p-Kaprekar number if the representation of its square in that base can be split into two parts, where the second part has p digits, that add up to the original number. The numbers are n ...

39000 to 39999

* 39304 = 34³ * 39559 = octahedral number * 39648 = tetranacci number

Primes

There are 958 prime numbers between 30000 and 40000.

References

{{Integers, 10 30000