78991872 has 40 divisors (see below), whose sum is σ = 210443376. Its totient is φ = 26330112.

The previous prime is 78991849. The next prime is 78991883. The reversal of 78991872 is 27819987.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24178 + ... + 27249.

Almost surely, 2^78991872 is an apocalyptic number.

It is an amenable number.

78991872 is an abundant number, since it is smaller than the sum of its proper divisors (131451504).

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

78991872 is an equidigital number, since it uses as much as digits as its factorization.

78991872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51448 (or 51432 counting only the distinct ones).

The product of its digits is 508032, while the sum is 51.

The square root of 78991872 is about 8887.7371698313. The cubic root of 78991872 is about 429.0693266068.

The spelling of 78991872 in words is "seventy-eight million, nine hundred ninety-one thousand, eight hundred seventy-two".