79515866 has 4 divisors (see below), whose sum is σ = 119273802. Its totient is φ = 39757932.

The previous prime is 79515859. The next prime is 79515871. The reversal of 79515866 is 66851597.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66851597 = 101 ⋅661897.

It can be written as a sum of positive squares in only one way, i.e., 77352025 + 2163841 = 8795^2 + 1471^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 79515866.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19878965 + ... + 19878968.

Almost surely, 2^79515866 is an apocalyptic number.

79515866 is a deficient number, since it is larger than the sum of its proper divisors (39757936).

79515866 is a wasteful number, since it uses less digits than its factorization.

79515866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39757935.

The product of its digits is 453600, while the sum is 47.

The square root of 79515866 is about 8917.1669267767. The cubic root of 79515866 is about 430.0159828204.

It can be divided in two parts, 795 and 15866, that added together give a palindrome (16661).

The spelling of 79515866 in words is "seventy-nine million, five hundred fifteen thousand, eight hundred sixty-six".