77385728 has 52 divisors (see below), whose sum is σ = 176925600. Its totient is φ = 33153024.

The previous prime is 77385713. The next prime is 77385739. The reversal of 77385728 is 82758377.

It is a happy number.

It is a super-4 number, since 4×77385728⁴ (a number of 33 digits) contains 4444 as substring.

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, 27323 + ... + 30021.

Almost surely, 2^77385728 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 77385728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88462800).

77385728 is an abundant number, since it is smaller than the sum of its proper divisors (99539872).

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

77385728 is an equidigital number, since it uses as much as digits as its factorization.

77385728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2730 (or 2708 counting only the distinct ones).

The product of its digits is 658560, while the sum is 47.

The square root of 77385728 is about 8796.9158231735. The cubic root of 77385728 is about 426.1412978058.

The spelling of 77385728 in words is "seventy-seven million, three hundred eighty-five thousand, seven hundred twenty-eight".