77864520 has 32 divisors (see below), whose sum is σ = 233593920. Its totient is φ = 20763840.

The previous prime is 77864513. The next prime is 77864551. The reversal of 77864520 is 2546877.

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, 324316 + ... + 324555.

It is an arithmetic number, because the mean of its divisors is an integer number (7299810).

Almost surely, 2^77864520 is an apocalyptic number.

It is an amenable number.

77864520 is an abundant number, since it is smaller than the sum of its proper divisors (155729400).

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

77864520 is a wasteful number, since it uses less digits than its factorization.

77864520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648885 (or 648881 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 39.

The square root of 77864520 is about 8824.0874882336. The cubic root of 77864520 is about 427.0183488249.

The spelling of 77864520 in words is "seventy-seven million, eight hundred sixty-four thousand, five hundred twenty".