77645664 has 72 divisors (see below), whose sum is σ = 233808120. Its totient is φ = 24357888.

The previous prime is 77645651. The next prime is 77645683. The reversal of 77645664 is 46654677.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3034 + ... + 12825.

It is an arithmetic number, because the mean of its divisors is an integer number (3247335).

Almost surely, 2^77645664 is an apocalyptic number.

It is an amenable number.

77645664 is an abundant number, since it is smaller than the sum of its proper divisors (156162456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77645664 is a wasteful number, since it uses less digits than its factorization.

77645664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15892 (or 15881 counting only the distinct ones).

The product of its digits is 846720, while the sum is 45.

The square root of 77645664 is about 8811.6777063168. The cubic root of 77645664 is about 426.6178959011.

The spelling of 77645664 in words is "seventy-seven million, six hundred forty-five thousand, six hundred sixty-four".