78891864 has 32 divisors (see below), whose sum is σ = 197845440. Its totient is φ = 26215200.

The previous prime is 78891853. The next prime is 78891871. The reversal of 78891864 is 46819887.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2979 + ... + 12909.

It is an arithmetic number, because the mean of its divisors is an integer number (6182670).

Almost surely, 2^78891864 is an apocalyptic number.

It is an amenable number.

78891864 is an abundant number, since it is smaller than the sum of its proper divisors (118953576).

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

78891864 is a wasteful number, since it uses less digits than its factorization.

78891864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10271 (or 10267 counting only the distinct ones).

The product of its digits is 774144, while the sum is 51.

The square root of 78891864 is about 8882.1092089661. The cubic root of 78891864 is about 428.8881751126. Note that the first 3 decimals are identical.

The spelling of 78891864 in words is "seventy-eight million, eight hundred ninety-one thousand, eight hundred sixty-four".