77677728 has 24 divisors (see below), whose sum is σ = 203904288. Its totient is φ = 25892544.

The previous prime is 77677727. The next prime is 77677741. The reversal of 77677728 is 82777677.

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (77677727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 404476 + ... + 404667.

It is an arithmetic number, because the mean of its divisors is an integer number (8496012).

Almost surely, 2^77677728 is an apocalyptic number.

It is an amenable number.

77677728 is an abundant number, since it is smaller than the sum of its proper divisors (126226560).

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

77677728 is a wasteful number, since it uses less digits than its factorization.

77677728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809156 (or 809148 counting only the distinct ones).

The product of its digits is 1613472, while the sum is 51.

The square root of 77677728 is about 8813.4969223345. The cubic root of 77677728 is about 426.6766121814.

Subtracting from 77677728 its sum of digits (51), we obtain a palindrome (77677677).

The spelling of 77677728 in words is "seventy-seven million, six hundred seventy-seven thousand, seven hundred twenty-eight".