77931128 has 64 divisors (see below), whose sum is σ = 170644320. Its totient is φ = 32972800.

The previous prime is 77931121. The next prime is 77931131. The reversal of 77931128 is 82113977.

It is a super-2 number, since 2×77931128² = 12146521422704768, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 77931091 and 77931100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77931121) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 168818 + ... + 169278.

Almost surely, 2^77931128 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 77931128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85322160).

77931128 is an abundant number, since it is smaller than the sum of its proper divisors (92713192).

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

77931128 is a wasteful number, since it uses less digits than its factorization.

77931128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608 (or 604 counting only the distinct ones).

The product of its digits is 21168, while the sum is 38.

The square root of 77931128 is about 8827.8608960495. The cubic root of 77931128 is about 427.1400762035.

The spelling of 77931128 in words is "seventy-seven million, nine hundred thirty-one thousand, one hundred twenty-eight".