15997939 has 4 divisors (see below), whose sum is σ = 16007040. Its totient is φ = 15988840.

The previous prime is 15997889. The next prime is 15997957. The reversal of 15997939 is 93979951.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15997939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15997979) 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, 979 + ... + 5740.

It is an arithmetic number, because the mean of its divisors is an integer number (4001760).

Almost surely, 2^15997939 is an apocalyptic number.

15997939 is a deficient number, since it is larger than the sum of its proper divisors (9101).

15997939 is an equidigital number, since it uses as much as digits as its factorization.

15997939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9100.

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

The square root of 15997939 is about 3999.7423667031. The cubic root of 15997939 is about 251.9733899424.

The spelling of 15997939 in words is "fifteen million, nine hundred ninety-seven thousand, nine hundred thirty-nine".