21656583068079 has 32 divisors (see below), whose sum is σ = 30090086963200. Its totient is φ = 13839332734080.

The previous prime is 21656583067997. The next prime is 21656583068083. The reversal of 21656583068079 is 97086038565612.

It is not a de Polignac number, because 21656583068079 - 2²³ = 21656574679471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21656583068089) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31172352 + ... + 31859514.

It is an arithmetic number, because the mean of its divisors is an integer number (940315217600).

Almost surely, 2^{21656583068079} is an apocalyptic number.

21656583068079 is a deficient number, since it is larger than the sum of its proper divisors (8433503895121).

21656583068079 is a wasteful number, since it uses less digits than its factorization.

21656583068079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690415.

The product of its (nonzero) digits is 130636800, while the sum is 66.

The spelling of 21656583068079 in words is "twenty-one trillion, six hundred fifty-six billion, five hundred eighty-three million, sixty-eight thousand, seventy-nine".