220656957921 has 16 divisors (see below), whose sum is σ = 328610718720. Its totient is φ = 146334453840.

The previous prime is 220656957887. The next prime is 220656958001. The reversal of 220656957921 is 129759656022.

220656957921 is a `hidden beast` number, since 2 + 2 + 0 + 6 + 5 + 69 + 579 + 2 + 1 = 666.

It is not a de Polignac number, because 220656957921 - 2⁷ = 220656957793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (220656956921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21388770 + ... + 21399083.

It is an arithmetic number, because the mean of its divisors is an integer number (20538169920).

Almost surely, 2^220656957921 is an apocalyptic number.

It is an amenable number.

220656957921 is a deficient number, since it is larger than the sum of its proper divisors (107953760799).

220656957921 is a wasteful number, since it uses less digits than its factorization.

220656957921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42788053 (or 42788047 counting only the distinct ones).

The product of its (nonzero) digits is 4082400, while the sum is 54.

The spelling of 220656957921 in words is "two hundred twenty billion, six hundred fifty-six million, nine hundred fifty-seven thousand, nine hundred twenty-one".