77765120 has 80 divisors (see below), whose sum is σ = 191726568. Its totient is φ = 30228480.

The previous prime is 77765111. The next prime is 77765141. The reversal of 77765120 is 2156777.

It can be written as a sum of positive squares in 4 ways, for example, as 68425984 + 9339136 = 8272^2 + 3056^2 .

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

It is a super-2 number, since 2×77765120² = 12094827777228800, which contains 22 as substring.

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, 94310 + ... + 95130.

Almost surely, 2^77765120 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 77765120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95863284).

77765120 is an abundant number, since it is smaller than the sum of its proper divisors (113961448).

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

77765120 is an equidigital number, since it uses as much as digits as its factorization.

77765120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881 (or 865 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 35.

The square root of 77765120 is about 8818.4533791363. The cubic root of 77765120 is about 426.8365642827.

The spelling of 77765120 in words is "seventy-seven million, seven hundred sixty-five thousand, one hundred twenty".