77664864 has 48 divisors (see below), whose sum is σ = 204325632. Its totient is φ = 25830528.

The previous prime is 77664863. The next prime is 77664869. The reversal of 77664864 is 46846677.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×77664864² = 12063662200276992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77664863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78517 + ... + 79499.

It is an arithmetic number, because the mean of its divisors is an integer number (4256784).

Almost surely, 2^77664864 is an apocalyptic number.

It is an amenable number.

77664864 is an abundant number, since it is smaller than the sum of its proper divisors (126660768).

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

77664864 is a wasteful number, since it uses less digits than its factorization.

77664864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819 (or 1811 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 48.

The square root of 77664864 is about 8812.7671023351. The cubic root of 77664864 is about 426.6530572916.

The spelling of 77664864 in words is "seventy-seven million, six hundred sixty-four thousand, eight hundred sixty-four".