78509975 has 24 divisors (see below), whose sum is σ = 100499520. Its totient is φ = 60808320.

The previous prime is 78509969. The next prime is 78509983. The reversal of 78509975 is 57990587.

It is not a de Polignac number, because 78509975 - 2⁸ = 78509719 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 127769 + ... + 128381.

It is an arithmetic number, because the mean of its divisors is an integer number (4187480).

Almost surely, 2^78509975 is an apocalyptic number.

78509975 is a deficient number, since it is larger than the sum of its proper divisors (21989545).

78509975 is a wasteful number, since it uses less digits than its factorization.

78509975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779 (or 774 counting only the distinct ones).

The product of its (nonzero) digits is 793800, while the sum is 50.

The square root of 78509975 is about 8860.5854772695. The cubic root of 78509975 is about 428.1950209589.

The spelling of 78509975 in words is "seventy-eight million, five hundred nine thousand, nine hundred seventy-five".