15399979 has 8 divisors (see below), whose sum is σ = 17756640. Its totient is φ = 13082496.

The previous prime is 15399959. The next prime is 15399983. The reversal of 15399979 is 97999351.

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

It is not a de Polignac number, because 15399979 - 2⁵ = 15399947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15399929) 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, 8944 + ... + 10525.

It is an arithmetic number, because the mean of its divisors is an integer number (2219580).

Almost surely, 2^15399979 is an apocalyptic number.

15399979 is a deficient number, since it is larger than the sum of its proper divisors (2356661).

15399979 is a wasteful number, since it uses less digits than its factorization.

15399979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19589.

The product of its digits is 688905, while the sum is 52.

The square root of 15399979 is about 3924.2806984210. The cubic root of 15399979 is about 248.7940803846.

The spelling of 15399979 in words is "fifteen million, three hundred ninety-nine thousand, nine hundred seventy-nine".