77664980 has 12 divisors (see below), whose sum is σ = 163096500. Its totient is φ = 31065984.

The previous prime is 77664973. The next prime is 77665019. The reversal of 77664980 is 8946677.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16418704 + 61246276 = 4052^2 + 7826^2 .

It is a congruent number.

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, 1941605 + ... + 1941644.

It is an arithmetic number, because the mean of its divisors is an integer number (13591375).

Almost surely, 2^77664980 is an apocalyptic number.

It is an amenable number.

77664980 is an abundant number, since it is smaller than the sum of its proper divisors (85431520).

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

77664980 is a wasteful number, since it uses less digits than its factorization.

77664980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3883258 (or 3883256 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 47.

The square root of 77664980 is about 8812.7736836935. The cubic root of 77664980 is about 426.6532697074.

It can be divided in two parts, 776 and 64980, that added together give a palindrome (65756).

The spelling of 77664980 in words is "seventy-seven million, six hundred sixty-four thousand, nine hundred eighty".