21556263162920 has 32 divisors (see below), whose sum is σ = 48502081042920. Its totient is φ = 8622418344960.

The previous prime is 21556263162899. The next prime is 21556263162943. The reversal of 21556263162920 is 2926136265512.

It can be written as a sum of positive squares in 4 ways, for example, as 21099635912356 + 456627250564 = 4593434^2 + 675742^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1377524 + ... + 6708956.

Almost surely, 2^{21556263162920} is an apocalyptic number.

21556263162920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21556263162920 is an abundant number, since it is smaller than the sum of its proper divisors (26945817880000).

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

21556263162920 is a wasteful number, since it uses less digits than its factorization.

21556263162920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5432525 (or 5432521 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 21556263162920 in words is "twenty-one trillion, five hundred fifty-six billion, two hundred sixty-three million, one hundred sixty-two thousand, nine hundred twenty".