77686128 has 240 divisors, whose sum is σ = 255921120. Its totient is φ = 22643712.

The previous prime is 77686097. The next prime is 77686171. The reversal of 77686128 is 82168677.

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 47 ways as a sum of consecutive naturals, for example, 1465750 + ... + 1465802.

It is an arithmetic number, because the mean of its divisors is an integer number (1066338).

Almost surely, 2^77686128 is an apocalyptic number.

77686128 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77686128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127960560).

77686128 is an abundant number, since it is smaller than the sum of its proper divisors (178234992).

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

77686128 is a wasteful number, since it uses less digits than its factorization.

77686128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 100 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 77686128 is about 8813.9734512874. The cubic root of 77686128 is about 426.6919917694.

The spelling of 77686128 in words is "seventy-seven million, six hundred eighty-six thousand, one hundred twenty-eight".