21656251635064 has 16 divisors (see below), whose sum is σ = 40605527214000. Its totient is φ = 10828111044672.

The previous prime is 21656251634999. The next prime is 21656251635143. The reversal of 21656251635064 is 46053615265612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6723084 + ... + 9408100.

It is an arithmetic number, because the mean of its divisors is an integer number (2537845450875).

Almost surely, 2^{21656251635064} is an apocalyptic number.

It is an amenable number.

21656251635064 is a deficient number, since it is larger than the sum of its proper divisors (18949275578936).

21656251635064 is a wasteful number, since it uses less digits than its factorization.

21656251635064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693222 (or 3693218 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 52.

The spelling of 21656251635064 in words is "twenty-one trillion, six hundred fifty-six billion, two hundred fifty-one million, six hundred thirty-five thousand, sixty-four".