79677509 has 2 divisors, whose sum is σ = 79677510. Its totient is φ = 79677508.

The previous prime is 79677491. The next prime is 79677511. The reversal of 79677509 is 90577697.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76615009 + 3062500 = 8753^2 + 1750^2 .

It is a cyclic number.

It is not a de Polignac number, because 79677509 - 2⁸ = 79677253 is a prime.

It is a Sophie Germain prime.

Together with 79677511, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79677569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39838754 + 39838755.

It is an arithmetic number, because the mean of its divisors is an integer number (39838755).

Almost surely, 2^79677509 is an apocalyptic number.

It is an amenable number.

79677509 is a deficient number, since it is larger than the sum of its proper divisors (1).

79677509 is an equidigital number, since it uses as much as digits as its factorization.

79677509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 833490, while the sum is 50.

The square root of 79677509 is about 8926.2259102042. The cubic root of 79677509 is about 430.3071701010.

The spelling of 79677509 in words is "seventy-nine million, six hundred seventy-seven thousand, five hundred nine".