18977651813 has 2 divisors, whose sum is σ = 18977651814. Its totient is φ = 18977651812.

The previous prime is 18977651807. The next prime is 18977651857. The reversal of 18977651813 is 31815677981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15875496004 + 3102155809 = 125998^2 + 55697^2 .

It is a cyclic number.

It is not a de Polignac number, because 18977651813 - 2³² = 14682684517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18977651113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9488825906 + 9488825907.

It is an arithmetic number, because the mean of its divisors is an integer number (9488825907).

Almost surely, 2^18977651813 is an apocalyptic number.

It is an amenable number.

18977651813 is a deficient number, since it is larger than the sum of its proper divisors (1).

18977651813 is an equidigital number, since it uses as much as digits as its factorization.

18977651813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2540160, while the sum is 56.

The spelling of 18977651813 in words is "eighteen billion, nine hundred seventy-seven million, six hundred fifty-one thousand, eight hundred thirteen".