78974909 has 16 divisors (see below), whose sum is σ = 88182192. Its totient is φ = 70253568.

The previous prime is 78974879. The next prime is 78974947. The reversal of 78974909 is 90947987.

It can be written as a sum of positive squares in 8 ways, for example, as 31684 + 78943225 = 178^2 + 8885^2 .

It is a cyclic number.

It is not a de Polignac number, because 78974909 - 2⁸ = 78974653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78974989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53627 + ... + 55079.

It is an arithmetic number, because the mean of its divisors is an integer number (5511387).

Almost surely, 2^78974909 is an apocalyptic number.

It is an amenable number.

78974909 is a deficient number, since it is larger than the sum of its proper divisors (9207283).

78974909 is a wasteful number, since it uses less digits than its factorization.

78974909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1616.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 78974909 is about 8886.7828261976. The cubic root of 78974909 is about 429.0386111089.

The spelling of 78974909 in words is "seventy-eight million, nine hundred seventy-four thousand, nine hundred nine".