77666944 has 64 divisors (see below), whose sum is σ = 161029440. Its totient is φ = 37287936.

The previous prime is 77666933. The next prime is 77666957. The reversal of 77666944 is 44966677.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 566844 + ... + 566980.

It is an arithmetic number, because the mean of its divisors is an integer number (2516085).

Almost surely, 2^77666944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77666944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80514720).

77666944 is an abundant number, since it is smaller than the sum of its proper divisors (83362496).

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

77666944 is a wasteful number, since it uses less digits than its factorization.

77666944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 285 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 49.

The square root of 77666944 is about 8812.8851121525. The cubic root of 77666944 is about 426.6568660943.

The spelling of 77666944 in words is "seventy-seven million, six hundred sixty-six thousand, nine hundred forty-four".