79715257 has 2 divisors, whose sum is σ = 79715258. Its totient is φ = 79715256.

The previous prime is 79715239. The next prime is 79715267. The reversal of 79715257 is 75251797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48846121 + 30869136 = 6989^2 + 5556^2 .

It is an emirp because it is prime and its reverse (75251797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79715257 - 2¹¹ = 79713209 is a prime.

It is not a weakly prime, because it can be changed into another prime (79715267) 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, 39857628 + 39857629.

It is an arithmetic number, because the mean of its divisors is an integer number (39857629).

Almost surely, 2^79715257 is an apocalyptic number.

It is an amenable number.

79715257 is a deficient number, since it is larger than the sum of its proper divisors (1).

79715257 is an equidigital number, since it uses as much as digits as its factorization.

79715257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 154350, while the sum is 43.

The square root of 79715257 is about 8928.3401032891. The cubic root of 79715257 is about 430.3751134509.

The spelling of 79715257 in words is "seventy-nine million, seven hundred fifteen thousand, two hundred fifty-seven".