15231989 has 4 divisors (see below), whose sum is σ = 15757260. Its totient is φ = 14706720.

The previous prime is 15231959. The next prime is 15231991. The reversal of 15231989 is 98913251.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98913251 = 307 ⋅322193.

It can be written as a sum of positive squares in 2 ways, for example, as 5880625 + 9351364 = 2425^2 + 3058^2 .

It is a cyclic number.

It is not a de Polignac number, because 15231989 - 2²⁰ = 14183413 is a prime.

It is a super-2 number, since 2×15231989² = 464026977792242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15231929) 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, 262592 + ... + 262649.

It is an arithmetic number, because the mean of its divisors is an integer number (3939315).

Almost surely, 2^15231989 is an apocalyptic number.

It is an amenable number.

15231989 is a deficient number, since it is larger than the sum of its proper divisors (525271).

15231989 is an equidigital number, since it uses as much as digits as its factorization.

15231989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525270.

The product of its digits is 19440, while the sum is 38.

The square root of 15231989 is about 3902.8180844103. The cubic root of 15231989 is about 247.8861177182.

The spelling of 15231989 in words is "fifteen million, two hundred thirty-one thousand, nine hundred eighty-nine".