15989 has 4 divisors (see below), whose sum is σ = 16320. Its totient is φ = 15660.

The previous prime is 15973. The next prime is 15991. The reversal of 15989 is 98951.

15989 = 72² + 73² + 74².

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98951 = 53 ⋅1867.

It is a cyclic number.

It is not a de Polignac number, because 15989 - 2⁴ = 15973 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 15989.

It is not an unprimeable number, because it can be changed into a prime (15919) 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, 77 + ... + 194.

It is an arithmetic number, because the mean of its divisors is an integer number (4080).

2¹⁵⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

15989 is a deficient number, since it is larger than the sum of its proper divisors (331).

15989 is an equidigital number, since it uses as much as digits as its factorization.

15989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330.

The product of its digits is 3240, while the sum is 32.

The square root of 15989 is about 126.4476176130. The cubic root of 15989 is about 25.1926450359.

The spelling of 15989 in words is "fifteen thousand, nine hundred eighty-nine".