249 has 4 divisors (see below), whose sum is σ = 336.
Its totient is φ = 164.
The previous prime is 241. The next prime is 251. The reversal of 249 is 942.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a trimorphic number since its cube, 15438249, ends in 249.
It is not a de Polignac number, because 249 - 23 = 241 is a prime.
It is a D-number.
It is a Curzon number.
It is a plaindrome in base 5, base 10, base 12, base 14 and base 15.
It is a nialpdrome in base 4 and base 16.
It is not an unprimeable number, because it can be changed into a prime (241) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39 + ... + 44.
It is an arithmetic number, because the mean of its divisors is an integer number (84).
It is an amenable number.
249 is a deficient number, since it is larger than the sum of its proper divisors (87).
249 is an equidigital number, since it uses as much as digits as its factorization.
249 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 86.
The product of its digits is 72, while the sum is 15.
The square root of 249 is about 15.7797338381.
The cubic root of 249 is about 6.2911945516.
The spelling of 249 in words is "two hundred forty-nine", and is thus an aban number.