79976509 has 2 divisors, whose sum is σ = 79976510. Its totient is φ = 79976508.

The previous prime is 79976489. The next prime is 79976549. The reversal of 79976509 is 90567997.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69672409 + 10304100 = 8347^2 + 3210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79976509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79976549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39988254 + 39988255.

It is an arithmetic number, because the mean of its divisors is an integer number (39988255).

Almost surely, 2^79976509 is an apocalyptic number.

It is an amenable number.

79976509 is a deficient number, since it is larger than the sum of its proper divisors (1).

79976509 is an equidigital number, since it uses as much as digits as its factorization.

79976509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1071630, while the sum is 52.

The square root of 79976509 is about 8942.9586267633. The cubic root of 79976509 is about 430.8447590232.

The spelling of 79976509 in words is "seventy-nine million, nine hundred seventy-six thousand, five hundred nine".