249 (two hundred
ndforty-nine) 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
248 and preceding
250.
Additionally, 249 is:
*a
Blum integer.
*a
semiprime
In mathematics, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other, so the semiprimes include the squares of prime numbers.
Because there are infinitely many prime n ...
.
*palindromic in base 82 (33
82).
*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 bases 3, 83, 84, 124, 167 and 247.
*the aliquot sum of any of these numbers: 375, 531, 1687, 4351, 7807, 12127, 14647 and 15151.
*part of the 3-aliquot tree. The aliquot sequence starting at 288 is: 288, 531, 249, 87, 33, 15, 9, 4, 3, 1, 0.
References
Integers
{{Num-stub