21154662112656 has 40 divisors (see below), whose sum is σ = 54654106627584. Its totient is φ = 7050965284480.

The previous prime is 21154662112627. The next prime is 21154662112741. The reversal of 21154662112656 is 65621126645112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

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, 17817456 + ... + 18967631.

Almost surely, 2^{21154662112656} is an apocalyptic number.

It is an amenable number.

21154662112656 is an abundant number, since it is smaller than the sum of its proper divisors (33499444514928).

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

21154662112656 is a wasteful number, since it uses less digits than its factorization.

21154662112656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36797079 (or 36797073 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 48.

Adding to 21154662112656 its reverse (65621126645112), we get a palindrome (86775788757768).

The spelling of 21154662112656 in words is "twenty-one trillion, one hundred fifty-four billion, six hundred sixty-two million, one hundred twelve thousand, six hundred fifty-six".