77931864 has 24 divisors (see below), whose sum is σ = 211065660. Its totient is φ = 25977264.

The previous prime is 77931853. The next prime is 77931869. The reversal of 77931864 is 46813977.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77931869) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 541122 + ... + 541265.

Almost surely, 2^77931864 is an apocalyptic number.

It is an amenable number.

77931864 is an abundant number, since it is smaller than the sum of its proper divisors (133133796).

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

77931864 is a wasteful number, since it uses less digits than its factorization.

77931864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1082399 (or 1082392 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 77931864 is about 8827.9025821539. The cubic root of 77931864 is about 427.1414208699.

The spelling of 77931864 in words is "seventy-seven million, nine hundred thirty-one thousand, eight hundred sixty-four".