1251565264 has 20 divisors (see below), whose sum is σ = 2552535040. Its totient is φ = 592846560.

The previous prime is 1251565261. The next prime is 1251565291. The reversal of 1251565264 is 4625651521.

It is a super-2 number, since 2×1251565264² = 3132831220102779392, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251565261) 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, 2058192 + ... + 2058799.

It is an arithmetic number, because the mean of its divisors is an integer number (127626752).

Almost surely, 2^1251565264 is an apocalyptic number.

It is an amenable number.

1251565264 is an abundant number, since it is smaller than the sum of its proper divisors (1300969776).

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

1251565264 is a wasteful number, since it uses less digits than its factorization.

1251565264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4117018 (or 4117012 counting only the distinct ones).

The product of its digits is 72000, while the sum is 37.

The square root of 1251565264 is about 35377.4683096459. The cubic root of 1251565264 is about 1077.6667920087. Note that the first 3 decimals are identical.

The spelling of 1251565264 in words is "one billion, two hundred fifty-one million, five hundred sixty-five thousand, two hundred sixty-four".