15957993 has 8 divisors (see below), whose sum is σ = 21595168. Its totient is φ = 10479744.

The previous prime is 15957971. The next prime is 15958003. The reversal of 15957993 is 39975951.

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

It is not a de Polignac number, because 15957993 - 2¹² = 15953897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15957913) 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, 39496 + ... + 39897.

It is an arithmetic number, because the mean of its divisors is an integer number (2699396).

Almost surely, 2^15957993 is an apocalyptic number.

It is an amenable number.

15957993 is a deficient number, since it is larger than the sum of its proper divisors (5637175).

15957993 is an equidigital number, since it uses as much as digits as its factorization.

15957993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79463.

The product of its digits is 382725, while the sum is 48.

The square root of 15957993 is about 3994.7456740073. The cubic root of 15957993 is about 251.7634937758.

The spelling of 15957993 in words is "fifteen million, nine hundred fifty-seven thousand, nine hundred ninety-three".