77947728 has 40 divisors (see below), whose sum is σ = 211965600. Its totient is φ = 24614784.

The previous prime is 77947717. The next prime is 77947757. The reversal of 77947728 is 82774977.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41823 + ... + 43646.

It is an arithmetic number, because the mean of its divisors is an integer number (5299140).

Almost surely, 2^77947728 is an apocalyptic number.

It is an amenable number.

77947728 is an abundant number, since it is smaller than the sum of its proper divisors (134017872).

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

77947728 is a wasteful number, since it uses less digits than its factorization.

77947728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85499 (or 85493 counting only the distinct ones).

The product of its digits is 1382976, while the sum is 51.

The square root of 77947728 is about 8828.8010511054. The cubic root of 77947728 is about 427.1704022194.

The spelling of 77947728 in words is "seventy-seven million, nine hundred forty-seven thousand, seven hundred twenty-eight".