56199937921 has 2 divisors, whose sum is σ = 56199937922. Its totient is φ = 56199937920.

The previous prime is 56199937907. The next prime is 56199937933. The reversal of 56199937921 is 12973999165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56116398321 + 83539600 = 236889^2 + 9140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56199937921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56199937921.

It is not a weakly prime, because it can be changed into another prime (56199737921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28099968960 + 28099968961.

It is an arithmetic number, because the mean of its divisors is an integer number (28099968961).

Almost surely, 2^56199937921 is an apocalyptic number.

It is an amenable number.

56199937921 is a deficient number, since it is larger than the sum of its proper divisors (1).

56199937921 is an equidigital number, since it uses as much as digits as its factorization.

56199937921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8266860, while the sum is 61.

The spelling of 56199937921 in words is "fifty-six billion, one hundred ninety-nine million, nine hundred thirty-seven thousand, nine hundred twenty-one".