78638924 has 48 divisors (see below), whose sum is σ = 172872000. Its totient is φ = 31102848.

The previous prime is 78638897. The next prime is 78638939. The reversal of 78638924 is 42983687.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15632 + ... + 20040.

It is an arithmetic number, because the mean of its divisors is an integer number (3601500).

Almost surely, 2^78638924 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 78638924, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86436000).

78638924 is an abundant number, since it is smaller than the sum of its proper divisors (94233076).

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

78638924 is a wasteful number, since it uses less digits than its factorization.

78638924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4447 (or 4431 counting only the distinct ones).

The product of its digits is 580608, while the sum is 47.

The square root of 78638924 is about 8867.8590426326. The cubic root of 78638924 is about 428.4293228964.

The spelling of 78638924 in words is "seventy-eight million, six hundred thirty-eight thousand, nine hundred twenty-four".