79999657 has 2 divisors, whose sum is σ = 79999658. Its totient is φ = 79999656.

The previous prime is 79999627. The next prime is 79999663. The reversal of 79999657 is 75699997.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48594841 + 31404816 = 6971^2 + 5604^2 .

It is a cyclic number.

It is not a de Polignac number, because 79999657 - 2¹⁹ = 79475369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 79999595 and 79999604.

It is not a weakly prime, because it can be changed into another prime (79999607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39999828 + 39999829.

It is an arithmetic number, because the mean of its divisors is an integer number (39999829).

Almost surely, 2^79999657 is an apocalyptic number.

It is an amenable number.

79999657 is a deficient number, since it is larger than the sum of its proper divisors (1).

79999657 is an equidigital number, since it uses as much as digits as its factorization.

79999657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9644670, while the sum is 61.

The square root of 79999657 is about 8944.2527356957. The cubic root of 79999657 is about 430.8863221962.

It can be divided in two parts, 79999 and 657, that added together give a square (80656 = 284²).

The spelling of 79999657 in words is "seventy-nine million, nine hundred ninety-nine thousand, six hundred fifty-seven".