78323815 has 4 divisors (see below), whose sum is σ = 93988584. Its totient is φ = 62659048.

The previous prime is 78323789. The next prime is 78323837. The reversal of 78323815 is 51832387.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51832387 = 463 ⋅111949.

It is a cyclic number.

It is not a de Polignac number, because 78323815 - 2¹⁷ = 78192743 is a prime.

It is a super-2 number, since 2×78323815² = 12269239992308450, which contains 22 as substring.

It is a Duffinian number.

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, 7832377 + ... + 7832386.

It is an arithmetic number, because the mean of its divisors is an integer number (23497146).

Almost surely, 2^78323815 is an apocalyptic number.

78323815 is a deficient number, since it is larger than the sum of its proper divisors (15664769).

78323815 is a wasteful number, since it uses less digits than its factorization.

78323815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15664768.

The product of its digits is 40320, while the sum is 37.

The square root of 78323815 is about 8850.0742934735. The cubic root of 78323815 is about 427.8563129486.

The spelling of 78323815 in words is "seventy-eight million, three hundred twenty-three thousand, eight hundred fifteen".