78479409 has 4 divisors (see below), whose sum is σ = 104639216. Its totient is φ = 52319604.

The previous prime is 78479393. The next prime is 78479411. The reversal of 78479409 is 90497487.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 78479409 - 2⁴ = 78479393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78479449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13079899 + ... + 13079904.

It is an arithmetic number, because the mean of its divisors is an integer number (26159804).

Almost surely, 2^78479409 is an apocalyptic number.

It is an amenable number.

78479409 is a deficient number, since it is larger than the sum of its proper divisors (26159807).

78479409 is a wasteful number, since it uses less digits than its factorization.

78479409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26159806.

The product of its (nonzero) digits is 508032, while the sum is 48.

The square root of 78479409 is about 8858.8604797683. The cubic root of 78479409 is about 428.1394445479.

The spelling of 78479409 in words is "seventy-eight million, four hundred seventy-nine thousand, four hundred nine".