264 (two hundred
ndsixty-four) is the
natural number
In mathematics, the natural numbers are the numbers 0, 1, 2, 3, and so on, possibly excluding 0. Some start counting with 0, defining the natural numbers as the non-negative integers , while others start with 1, defining them as the positive in ...
following
263 and preceding
265
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Year 265 (Roman numerals, CCLXV) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerianus and Lucillus (or, less frequently, year 1018 ''Ab urbe condita''). Th ...
.
In mathematics
264 is an even
composite number
A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Accordingly it is a positive integer that has at least one divisor other than 1 and itself. Every positive integer is composite, prime numb ...
with three distinct prime factors (2
3 × 3 × 11). 264 is a
Harshad number
In mathematics, a harshad number (or Niven number) in a given radix, number base is an integer that is divisible by the digit sum, sum of its digits when written in that base. Harshad numbers in base are also known as -harshad (or -Niven) numbers ...
in base ten, also divisible by each of its digits.
264 is the sum of all even
composite number
A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Accordingly it is a positive integer that has at least one divisor other than 1 and itself. Every positive integer is composite, prime numb ...
s that are not the sum of two
abundant number
In number theory, an abundant number or excessive number is a positive integer for which the sum of its proper divisors is greater than the number. The integer 12 is the first abundant number. Its proper divisors are 1, 2, 3, 4 and 6 for a total ...
s (not necessarily distinct):
4 +
6 +
8 +
10 +
12 +
14 +
16 +
18 +
20 +
22 +
26 +
28 +
34 +
46.
The only other even number that is not the sum of two abundant numbers is the only even
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime ...
,
2.
References
{{Integers, 2
Integers