6564139956 has 72 divisors (see below), whose sum is σ = 18590373984. Its totient is φ = 1935368640.

The previous prime is 6564139891. The next prime is 6564139961. The reversal of 6564139956 is 6599314656.

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, 209350 + ... + 238653.

Almost surely, 2^6564139956 is an apocalyptic number.

6564139956 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

6564139956 is an abundant number, since it is smaller than the sum of its proper divisors (12026234028).

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

6564139956 is a wasteful number, since it uses less digits than its factorization.

6564139956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448061 (or 448056 counting only the distinct ones).

The product of its digits is 5248800, while the sum is 54.

The square root of 6564139956 is about 81019.3801259921. The cubic root of 6564139956 is about 1872.3740383705.

The spelling of 6564139956 in words is "six billion, five hundred sixty-four million, one hundred thirty-nine thousand, nine hundred fifty-six".