21315366520056 has 96 divisors (see below), whose sum is σ = 66059968141440. Its totient is φ = 6082366227264.

The previous prime is 21315366520051. The next prime is 21315366520079. The reversal of 21315366520056 is 65002566351312.

21315366520056 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 536 + 65 + 2 + 0 + 0 + 56 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21315366519993 and 21315366520020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315366520051) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26472726 + ... + 27266021.

It is an arithmetic number, because the mean of its divisors is an integer number (688124668140).

Almost surely, 2^{21315366520056} is an apocalyptic number.

It is an amenable number.

21315366520056 is an abundant number, since it is smaller than the sum of its proper divisors (44744601621384).

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

21315366520056 is a wasteful number, since it uses less digits than its factorization.

21315366520056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53739553 (or 53739546 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The spelling of 21315366520056 in words is "twenty-one trillion, three hundred fifteen billion, three hundred sixty-six million, five hundred twenty thousand, fifty-six".