78928815 has 32 divisors (see below), whose sum is σ = 146704896. Its totient is φ = 35487360.

The previous prime is 78928799. The next prime is 78928853. The reversal of 78928815 is 51882987.

It is not a de Polignac number, because 78928815 - 2⁴ = 78928799 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244 + ... + 12566.

It is an arithmetic number, because the mean of its divisors is an integer number (4584528).

Almost surely, 2^78928815 is an apocalyptic number.

78928815 is a deficient number, since it is larger than the sum of its proper divisors (67776081).

78928815 is a wasteful number, since it uses less digits than its factorization.

78928815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12399.

The product of its digits is 322560, while the sum is 48.

The square root of 78928815 is about 8884.1890457149. The cubic root of 78928815 is about 428.9551248696.

The spelling of 78928815 in words is "seventy-eight million, nine hundred twenty-eight thousand, eight hundred fifteen".