251904 has 48 divisors (see below), whose sum is σ = 687960. Its totient is φ = 81920.

The previous prime is 251903. The next prime is 251917. The reversal of 251904 is 409152.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251903) 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, 6124 + ... + 6164.

2²⁵¹⁹⁰⁴ is an apocalyptic number.

251904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343980).

251904 is an abundant number, since it is smaller than the sum of its proper divisors (436056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251904 is an equidigital number, since it uses as much as digits as its factorization.

251904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 251904 is about 501.9003885235. The cubic root of 251904 is about 63.1555741837.

The spelling of 251904 in words is "two hundred fifty-one thousand, nine hundred four".