77856 has 24 divisors (see below), whose sum is σ = 204624. Its totient is φ = 25920.

The previous prime is 77849. The next prime is 77863. The reversal of 77856 is 65877.

It is an interprime number because it is at equal distance from previous prime (77849) and next prime (77863).

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 310 + ... + 501.

It is an arithmetic number, because the mean of its divisors is an integer number (8526).

2⁷⁷⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

77856 is an abundant number, since it is smaller than the sum of its proper divisors (126768).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102312).

77856 is a wasteful number, since it uses less digits than its factorization.

77856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 816 counting only the distinct ones).

The product of its digits is 11760, while the sum is 33.

The square root of 77856 is about 279.0268804255. The cubic root of 77856 is about 42.7002773357.

The spelling of 77856 in words is "seventy-seven thousand, eight hundred fifty-six".