21213455110056 has 48 divisors (see below), whose sum is σ = 62676117372960. Its totient is φ = 6428319730080.

The previous prime is 21213455110051. The next prime is 21213455110079. The reversal of 21213455110056 is 65001155431212.

21213455110056 is a `hidden beast` number, since 2 + 1 + 2 + 134 + 5 + 511 + 0 + 0 + 5 + 6 = 666.

It is a super-2 number, since 2×21213455110056² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21213455110056.

It is not an unprimeable number, because it can be changed into a prime (21213455110051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13392331980 + ... + 13392333563.

It is an arithmetic number, because the mean of its divisors is an integer number (1305752445270).

Almost surely, 2^{21213455110056} is an apocalyptic number.

It is an amenable number.

21213455110056 is an abundant number, since it is smaller than the sum of its proper divisors (41462662262904).

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

21213455110056 is a wasteful number, since it uses less digits than its factorization.

21213455110056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26784665566 (or 26784665559 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The spelling of 21213455110056 in words is "twenty-one trillion, two hundred thirteen billion, four hundred fifty-five million, one hundred ten thousand, fifty-six".