78739812 has 18 divisors (see below), whose sum is σ = 199036838. Its totient is φ = 26246592.

The previous prime is 78739769. The next prime is 78739823. The reversal of 78739812 is 21893787.

It can be written as a sum of positive squares in only one way, i.e., 75585636 + 3154176 = 8694^2 + 1776^2 .

It is a tau number, because it is divible by the number of its divisors (18).

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 5 ways as a sum of consecutive naturals, for example, 1093573 + ... + 1093644.

Almost surely, 2^78739812 is an apocalyptic number.

It is an amenable number.

78739812 is an abundant number, since it is smaller than the sum of its proper divisors (120297026).

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

78739812 is a wasteful number, since it uses less digits than its factorization.

78739812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2187227 (or 2187222 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 78739812 is about 8873.5456273127. The cubic root of 78739812 is about 428.6124591193.

The spelling of 78739812 in words is "seventy-eight million, seven hundred thirty-nine thousand, eight hundred twelve".