251965560 has 384 divisors, whose sum is σ = 989775360. Its totient is φ = 50181120.

The previous prime is 251965547. The next prime is 251965589. The reversal of 251965560 is 65569152.

251965560 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×251965560² = 126973286852227200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3760647 + ... + 3760713.

It is an arithmetic number, because the mean of its divisors is an integer number (2577540).

Almost surely, 2^251965560 is an apocalyptic number.

251965560 is a gapful number since it is divisible by the number (20) 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 251965560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (494887680).

251965560 is an abundant number, since it is smaller than the sum of its proper divisors (737809800).

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

251965560 is a wasteful number, since it uses less digits than its factorization.

251965560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 39.

The square root of 251965560 is about 15873.4230712849. The cubic root of 251965560 is about 631.6071839276.

The spelling of 251965560 in words is "two hundred fifty-one million, nine hundred sixty-five thousand, five hundred sixty".