20643525550656 has 84 divisors (see below), whose sum is σ = 59177730213264. Its totient is φ = 6880385376000.

The previous prime is 20643525550639. The next prime is 20643525550699. The reversal of 20643525550656 is 65605552534602.

20643525550656 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 3 + 5 + 25 + 550 + 65 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2976631 + ... + 7081481.

Almost surely, 2^{20643525550656} is an apocalyptic number.

It is an amenable number.

20643525550656 is an abundant number, since it is smaller than the sum of its proper divisors (38534204662608).

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

20643525550656 is a wasteful number, since it uses less digits than its factorization.

20643525550656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4113600 (or 4113587 counting only the distinct ones).

The product of its (nonzero) digits is 32400000, while the sum is 54.

The spelling of 20643525550656 in words is "twenty trillion, six hundred forty-three billion, five hundred twenty-five million, five hundred fifty thousand, six hundred fifty-six".