21156677712 has 50 divisors (see below), whose sum is σ = 61233567098. Its totient is φ = 7052225472.

The previous prime is 21156677693. The next prime is 21156677753. The reversal of 21156677712 is 21777665112.

21156677712 is a `hidden beast` number, since 2 + 1 + 1 + 566 + 7 + 77 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20057357376 + 1099320336 = 141624^2 + 33156^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8161003 + ... + 8163594.

Almost surely, 2^21156677712 is an apocalyptic number.

It is an amenable number.

21156677712 is an abundant number, since it is smaller than the sum of its proper divisors (40076889386).

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

21156677712 is a wasteful number, since it uses less digits than its factorization.

21156677712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16324617 (or 16324602 counting only the distinct ones).

The product of its digits is 246960, while the sum is 45.

The spelling of 21156677712 in words is "twenty-one billion, one hundred fifty-six million, six hundred seventy-seven thousand, seven hundred twelve".