15699979 has 2 divisors, whose sum is σ = 15699980. Its totient is φ = 15699978.

The previous prime is 15699967. The next prime is 15699989. The reversal of 15699979 is 97999651.

15699979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15699979 - 2¹⁹ = 15175691 is a prime.

It is not a weakly prime, because it can be changed into another prime (15699949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7849989 + 7849990.

It is an arithmetic number, because the mean of its divisors is an integer number (7849990).

Almost surely, 2^15699979 is an apocalyptic number.

15699979 is a deficient number, since it is larger than the sum of its proper divisors (1).

15699979 is an equidigital number, since it uses as much as digits as its factorization.

15699979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1377810, while the sum is 55.

The square root of 15699979 is about 3962.3199012700. The cubic root of 15699979 is about 250.3992500581.

The spelling of 15699979 in words is "fifteen million, six hundred ninety-nine thousand, nine hundred seventy-nine".