78117985 has 16 divisors (see below), whose sum is σ = 105564672. Its totient is φ = 54979200.

The previous prime is 78117983. The next prime is 78118031. The reversal of 78117985 is 58971187.

It is not a de Polignac number, because 78117985 - 2¹ = 78117983 is a prime.

It is a super-2 number, since 2×78117985² = 12204839160920450, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 21204 + ... + 24613.

It is an arithmetic number, because the mean of its divisors is an integer number (6597792).

Almost surely, 2^78117985 is an apocalyptic number.

It is an amenable number.

78117985 is a deficient number, since it is larger than the sum of its proper divisors (27446687).

78117985 is a wasteful number, since it uses less digits than its factorization.

78117985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45864.

The product of its digits is 141120, while the sum is 46.

The square root of 78117985 is about 8838.4379275978. The cubic root of 78117985 is about 427.4811911062.

The spelling of 78117985 in words is "seventy-eight million, one hundred seventeen thousand, nine hundred eighty-five".