251565264 has 120 divisors (see below), whose sum is σ = 739327680. Its totient is φ = 82798848.

The previous prime is 251565241. The next prime is 251565287. The reversal of 251565264 is 462565152.

It is an interprime number because it is at equal distance from previous prime (251565241) and next prime (251565287).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 345669 + ... + 346395.

It is an arithmetic number, because the mean of its divisors is an integer number (6161064).

Almost surely, 2^251565264 is an apocalyptic number.

251565264 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 251565264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369663840).

251565264 is an abundant number, since it is smaller than the sum of its proper divisors (487762416).

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

251565264 is an equidigital number, since it uses as much as digits as its factorization.

251565264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 839 (or 821 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 251565264 is about 15860.8090588091. The cubic root of 251565264 is about 631.2725299412.

The spelling of 251565264 in words is "two hundred fifty-one million, five hundred sixty-five thousand, two hundred sixty-four".