78406664 has 24 divisors (see below), whose sum is σ = 171015390. Its totient is φ = 33602688.

The previous prime is 78406651. The next prime is 78406687. The reversal of 78406664 is 46660487.

It can be written as a sum of positive squares in only one way, i.e., 76562500 + 1844164 = 8750^2 + 1358^2 .

It is a super-2 number, since 2×78406664² = 12295209919217792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 99617 + ... + 100400.

Almost surely, 2^78406664 is an apocalyptic number.

It is an amenable number.

78406664 is an abundant number, since it is smaller than the sum of its proper divisors (92608726).

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

78406664 is a wasteful number, since it uses less digits than its factorization.

78406664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200037 (or 200026 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 41.

The square root of 78406664 is about 8854.7537515168. The cubic root of 78406664 is about 428.0071184072.

The spelling of 78406664 in words is "seventy-eight million, four hundred six thousand, six hundred sixty-four".