77777880 has 64 divisors (see below), whose sum is σ = 233940960. Its totient is φ = 20686848.

The previous prime is 77777879. The next prime is 77777891. The reversal of 77777880 is 8877777.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70614 + ... + 71706.

Almost surely, 2^77777880 is an apocalyptic number.

It is an amenable number.

77777880 is an abundant number, since it is smaller than the sum of its proper divisors (156163080).

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

77777880 is a wasteful number, since it uses less digits than its factorization.

77777880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 1075648, while the sum is 51.

The square root of 77777880 is about 8819.1768323353. The cubic root of 77777880 is about 426.8599086676.

The spelling of 77777880 in words is "seventy-seven million, seven hundred seventy-seven thousand, eight hundred eighty".