1251375664 has 40 divisors (see below), whose sum is σ = 3022806528. Its totient is φ = 487548480.

The previous prime is 1251375623. The next prime is 1251375677. The reversal of 1251375664 is 4665731521.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 506632 + ... + 509095.

Almost surely, 2^1251375664 is an apocalyptic number.

1251375664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1251375664 is an abundant number, since it is smaller than the sum of its proper divisors (1771430864).

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

1251375664 is a wasteful number, since it uses less digits than its factorization.

1251375664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015753 (or 1015747 counting only the distinct ones).

The product of its digits is 151200, while the sum is 40.

The square root of 1251375664 is about 35374.7885364704. The cubic root of 1251375664 is about 1077.6123705712.

The spelling of 1251375664 in words is "one billion, two hundred fifty-one million, three hundred seventy-five thousand, six hundred sixty-four".