78117986 has 16 divisors (see below), whose sum is σ = 118324800. Its totient is φ = 38678640.

The previous prime is 78117983. The next prime is 78118031. The reversal of 78117986 is 68971187.

It is a super-2 number, since 2×78117986² = 12204839473392392, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78117986.

It is not an unprimeable number, because it can be changed into a prime (78117983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130115 + ... + 130713.

It is an arithmetic number, because the mean of its divisors is an integer number (7395300).

Almost surely, 2^78117986 is an apocalyptic number.

78117986 is a deficient number, since it is larger than the sum of its proper divisors (40206814).

78117986 is a wasteful number, since it uses less digits than its factorization.

78117986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1129.

The product of its digits is 169344, while the sum is 47.

The square root of 78117986 is about 8838.4379841689. The cubic root of 78117986 is about 427.4811929303.

The spelling of 78117986 in words is "seventy-eight million, one hundred seventeen thousand, nine hundred eighty-six".