21115746056 has 8 divisors (see below), whose sum is σ = 39592023870. Its totient is φ = 10557873024.

The previous prime is 21115746049. The next prime is 21115746097. The reversal of 21115746056 is 65064751112.

It can be written as a sum of positive squares in only one way, i.e., 21114996100 + 749956 = 145310^2 + 866^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1319734121 + ... + 1319734136.

Almost surely, 2^21115746056 is an apocalyptic number.

It is an amenable number.

21115746056 is a deficient number, since it is larger than the sum of its proper divisors (18476277814).

21115746056 is a wasteful number, since it uses less digits than its factorization.

21115746056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2639468263 (or 2639468259 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 38.

The spelling of 21115746056 in words is "twenty-one billion, one hundred fifteen million, seven hundred forty-six thousand, fifty-six".