78996815 has 4 divisors (see below), whose sum is σ = 94796184. Its totient is φ = 63197448.

The previous prime is 78996787. The next prime is 78996821. The reversal of 78996815 is 51869987.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78996815 - 2¹⁴ = 78980431 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7899677 + ... + 7899686.

It is an arithmetic number, because the mean of its divisors is an integer number (23699046).

Almost surely, 2^78996815 is an apocalyptic number.

78996815 is a deficient number, since it is larger than the sum of its proper divisors (15799369).

78996815 is a wasteful number, since it uses less digits than its factorization.

78996815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15799368.

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

The square root of 78996815 is about 8888.0152452615. The cubic root of 78996815 is about 429.0782762425.

The spelling of 78996815 in words is "seventy-eight million, nine hundred ninety-six thousand, eight hundred fifteen".