251387640264 has 16 divisors (see below), whose sum is σ = 628469100720. Its totient is φ = 83795880080.

The previous prime is 251387640253. The next prime is 251387640281. The reversal of 251387640264 is 462046783152.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5237242482 + ... + 5237242529.

It is an arithmetic number, because the mean of its divisors is an integer number (39279318795).

Almost surely, 2^251387640264 is an apocalyptic number.

251387640264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

251387640264 is an abundant number, since it is smaller than the sum of its proper divisors (377081460456).

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

251387640264 is a wasteful number, since it uses less digits than its factorization.

251387640264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10474485020 (or 10474485016 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 48.

The spelling of 251387640264 in words is "two hundred fifty-one billion, three hundred eighty-seven million, six hundred forty thousand, two hundred sixty-four".