79578297172817 has 2 divisors, whose sum is σ = 79578297172818. Its totient is φ = 79578297172816.

The previous prime is 79578297172799. The next prime is 79578297172823. The reversal of 79578297172817 is 71827179287597.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59761697063761 + 19816600109056 = 7730569^2 + 4451584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79578297172817 is a prime.

It is not a weakly prime, because it can be changed into another prime (79578297172837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39789148586408 + 39789148586409.

It is an arithmetic number, because the mean of its divisors is an integer number (39789148586409).

Almost surely, 2^{79578297172817} is an apocalyptic number.

It is an amenable number.

79578297172817 is a deficient number, since it is larger than the sum of its proper divisors (1).

79578297172817 is an equidigital number, since it uses as much as digits as its factorization.

79578297172817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1742549760, while the sum is 80.

The spelling of 79578297172817 in words is "seventy-nine trillion, five hundred seventy-eight billion, two hundred ninety-seven million, one hundred seventy-two thousand, eight hundred seventeen".