77257680 has 80 divisors (see below), whose sum is σ = 240353664. Its totient is φ = 20528640.

The previous prime is 77257679. The next prime is 77257709. The reversal of 77257680 is 8675277.

It is a tau number, because it is divible by the number of its divisors (80).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116550 + ... + 117210.

Almost surely, 2^77257680 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 77257680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120176832).

77257680 is an abundant number, since it is smaller than the sum of its proper divisors (163095984).

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

77257680 is a wasteful number, since it uses less digits than its factorization.

77257680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1164 (or 1158 counting only the distinct ones).

The product of its (nonzero) digits is 164640, while the sum is 42.

The square root of 77257680 is about 8789.6348047004. The cubic root of 77257680 is about 425.9061266850.

The spelling of 77257680 in words is "seventy-seven million, two hundred fifty-seven thousand, six hundred eighty".