77978886 has 16 divisors (see below), whose sum is σ = 156244464. Its totient is φ = 25945184.

The previous prime is 77978839. The next prime is 77978897. The reversal of 77978886 is 68887977.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8325 + ... + 15008.

It is an arithmetic number, because the mean of its divisors is an integer number (9765279).

Almost surely, 2^77978886 is an apocalyptic number.

77978886 is an abundant number, since it is smaller than the sum of its proper divisors (78265578).

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

77978886 is a wasteful number, since it uses less digits than its factorization.

77978886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23895.

The product of its digits is 9483264, while the sum is 60.

The square root of 77978886 is about 8830.5654405593. The cubic root of 77978886 is about 427.2273121627.

Subtracting from 77978886 its reverse (68887977), we obtain a palindrome (9090909).

The spelling of 77978886 in words is "seventy-seven million, nine hundred seventy-eight thousand, eight hundred eighty-six".