78865866 has 16 divisors (see below), whose sum is σ = 175257600. Its totient is φ = 26288604.

The previous prime is 78865817. The next prime is 78865883. The reversal of 78865866 is 66856887.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 1460479 = 78865866 / (7 + 8 + 8 + 6 + 5 + 8 + 6 + 6).

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, 730186 + ... + 730293.

It is an arithmetic number, because the mean of its divisors is an integer number (10953600).

Almost surely, 2^78865866 is an apocalyptic number.

78865866 is an abundant number, since it is smaller than the sum of its proper divisors (96391734).

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

78865866 is a wasteful number, since it uses less digits than its factorization.

78865866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460490 (or 1460484 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The square root of 78865866 is about 8880.6455846408. The cubic root of 78865866 is about 428.8410580453.

The spelling of 78865866 in words is "seventy-eight million, eight hundred sixty-five thousand, eight hundred sixty-six".