21839589 has 6 divisors (see below), whose sum is σ = 31546086. Its totient is φ = 14559720.

The previous prime is 21839563. The next prime is 21839591. The reversal of 21839589 is 98593812.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15920100 + 5919489 = 3990^2 + 2433^2 .

It is not a de Polignac number, because 21839589 - 2⁵ = 21839557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21839599) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1213302 + ... + 1213319.

It is an arithmetic number, because the mean of its divisors is an integer number (5257681).

Almost surely, 2^21839589 is an apocalyptic number.

It is an amenable number.

21839589 is a deficient number, since it is larger than the sum of its proper divisors (9706497).

21839589 is a wasteful number, since it uses less digits than its factorization.

21839589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2426627 (or 2426624 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 21839589 is about 4673.2846050717. The cubic root of 21839589 is about 279.5212439437.

The spelling of 21839589 in words is "twenty-one million, eight hundred thirty-nine thousand, five hundred eighty-nine".