77915668 has 12 divisors (see below), whose sum is σ = 136846612. Its totient is φ = 38816640.

The previous prime is 77915659. The next prime is 77915693. The reversal of 77915668 is 86651977.

It can be written as a sum of positive squares in 2 ways, for example, as 48191364 + 29724304 = 6942^2 + 5452^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34053 + ... + 36268.

Almost surely, 2^77915668 is an apocalyptic number.

It is an amenable number.

77915668 is a deficient number, since it is larger than the sum of its proper divisors (58930944).

77915668 is a wasteful number, since it uses less digits than its factorization.

77915668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70602 (or 70600 counting only the distinct ones).

The product of its digits is 635040, while the sum is 49.

The square root of 77915668 is about 8826.9852158027. The cubic root of 77915668 is about 427.1118289444. Note that the first 3 decimals are identical.

The spelling of 77915668 in words is "seventy-seven million, nine hundred fifteen thousand, six hundred sixty-eight".