79916569 has 2 divisors, whose sum is σ = 79916570. Its totient is φ = 79916568.

The previous prime is 79916561. The next prime is 79916579. The reversal of 79916569 is 96561997.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51667344 + 28249225 = 7188^2 + 5315^2 .

It is a cyclic number.

It is not a de Polignac number, because 79916569 - 2³ = 79916561 is a prime.

It is a super-2 number, since 2×79916569² = 12773316001463522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (79916561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39958284 + 39958285.

It is an arithmetic number, because the mean of its divisors is an integer number (39958285).

Almost surely, 2^79916569 is an apocalyptic number.

It is an amenable number.

79916569 is a deficient number, since it is larger than the sum of its proper divisors (1).

79916569 is an equidigital number, since it uses as much as digits as its factorization.

79916569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 918540, while the sum is 52.

The square root of 79916569 is about 8939.6067586891. The cubic root of 79916569 is about 430.7370970380.

The spelling of 79916569 in words is "seventy-nine million, nine hundred sixteen thousand, five hundred sixty-nine".