79721598997 has 2 divisors, whose sum is σ = 79721598998. Its totient is φ = 79721598996.

The previous prime is 79721598961. The next prime is 79721599003. The reversal of 79721598997 is 79989512797.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44704336356 + 35017262641 = 211434^2 + 187129^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79721598997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79721598907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39860799498 + 39860799499.

It is an arithmetic number, because the mean of its divisors is an integer number (39860799499).

Almost surely, 2^79721598997 is an apocalyptic number.

It is an amenable number.

79721598997 is a deficient number, since it is larger than the sum of its proper divisors (1).

79721598997 is an equidigital number, since it uses as much as digits as its factorization.

79721598997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180033840, while the sum is 73.

The spelling of 79721598997 in words is "seventy-nine billion, seven hundred twenty-one million, five hundred ninety-eight thousand, nine hundred ninety-seven".