78986915 has 32 divisors (see below), whose sum is σ = 114487296. Its totient is φ = 51166080.

The previous prime is 78986911. The next prime is 78986917. The reversal of 78986915 is 51968987.

It is not a de Polignac number, because 78986915 - 2² = 78986911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78986911) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45809 + ... + 47501.

It is an arithmetic number, because the mean of its divisors is an integer number (3577728).

Almost surely, 2^78986915 is an apocalyptic number.

78986915 is a deficient number, since it is larger than the sum of its proper divisors (35500381).

78986915 is a wasteful number, since it uses less digits than its factorization.

78986915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1779.

The product of its digits is 1088640, while the sum is 53.

The square root of 78986915 is about 8887.4582980738. The cubic root of 78986915 is about 429.0603512481.

The spelling of 78986915 in words is "seventy-eight million, nine hundred eighty-six thousand, nine hundred fifteen".