78549979 has 8 divisors (see below), whose sum is σ = 83522880. Its totient is φ = 73616256.

The previous prime is 78549967. The next prime is 78549983. The reversal of 78549979 is 97994587.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78549979 - 2⁹ = 78549467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78549959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5604 + ... + 13729.

It is an arithmetic number, because the mean of its divisors is an integer number (10440360).

Almost surely, 2^78549979 is an apocalyptic number.

78549979 is a deficient number, since it is larger than the sum of its proper divisors (4972901).

78549979 is a wasteful number, since it uses less digits than its factorization.

78549979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19589.

The product of its digits is 5715360, while the sum is 58.

The square root of 78549979 is about 8862.8426026868. The cubic root of 78549979 is about 428.2677361565.

The spelling of 78549979 in words is "seventy-eight million, five hundred forty-nine thousand, nine hundred seventy-nine".