79980606721 has 2 divisors, whose sum is σ = 79980606722. Its totient is φ = 79980606720.

The previous prime is 79980606691. The next prime is 79980606731. The reversal of 79980606721 is 12760608997.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63149177025 + 16831429696 = 251295^2 + 129736^2 .

It is a cyclic number.

It is not a de Polignac number, because 79980606721 - 2²³ = 79972218113 is a prime.

It is not a weakly prime, because it can be changed into another prime (79980606731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39990303360 + 39990303361.

It is an arithmetic number, because the mean of its divisors is an integer number (39990303361).

Almost surely, 2^79980606721 is an apocalyptic number.

It is an amenable number.

79980606721 is a deficient number, since it is larger than the sum of its proper divisors (1).

79980606721 is an equidigital number, since it uses as much as digits as its factorization.

79980606721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2286144, while the sum is 55.

The spelling of 79980606721 in words is "seventy-nine billion, nine hundred eighty million, six hundred six thousand, seven hundred twenty-one".