78009975 has 18 divisors (see below), whose sum is σ = 139724936. Its totient is φ = 41605200.

The previous prime is 78009941. The next prime is 78009983. The reversal of 78009975 is 57990087.

It is not a de Polignac number, because 78009975 - 2²³ = 69621367 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78009975.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 173131 + ... + 173580.

Almost surely, 2^78009975 is an apocalyptic number.

78009975 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

78009975 is a deficient number, since it is larger than the sum of its proper divisors (61714961).

78009975 is a wasteful number, since it uses less digits than its factorization.

78009975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346727 (or 346719 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 45.

The square root of 78009975 is about 8832.3255714449. The cubic root of 78009975 is about 427.2840809705.

The spelling of 78009975 in words is "seventy-eight million, nine thousand, nine hundred seventy-five".