79691977 has 2 divisors, whose sum is σ = 79691978. Its totient is φ = 79691976.

The previous prime is 79691939. The next prime is 79691993. The reversal of 79691977 is 77919697.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78570496 + 1121481 = 8864^2 + 1059^2 .

It is a cyclic number.

It is not a de Polignac number, because 79691977 - 2¹⁹ = 79167689 is a prime.

It is a super-2 number, since 2×79691977² = 12701622396337058, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (79691177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39845988 + 39845989.

It is an arithmetic number, because the mean of its divisors is an integer number (39845989).

Almost surely, 2^79691977 is an apocalyptic number.

It is an amenable number.

79691977 is a deficient number, since it is larger than the sum of its proper divisors (1).

79691977 is an equidigital number, since it uses as much as digits as its factorization.

79691977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1500282, while the sum is 55.

The square root of 79691977 is about 8927.0362943140. The cubic root of 79691977 is about 430.3332138677. Note that the first 3 decimals are identical.

The spelling of 79691977 in words is "seventy-nine million, six hundred ninety-one thousand, nine hundred seventy-seven".