20989239 has 8 divisors (see below), whose sum is σ = 28014960. Its totient is φ = 13978176.

The previous prime is 20989229. The next prime is 20989279. The reversal of 20989239 is 93298902.

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

It is not a de Polignac number, because 20989239 - 2⁴ = 20989223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20989239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989229) 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, 289 + ... + 6485.

It is an arithmetic number, because the mean of its divisors is an integer number (3501870).

Almost surely, 2^20989239 is an apocalyptic number.

20989239 is a deficient number, since it is larger than the sum of its proper divisors (7025721).

20989239 is a wasteful number, since it uses less digits than its factorization.

20989239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7329.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 20989239 is about 4581.4014231455. The cubic root of 20989239 is about 275.8452845339.

The spelling of 20989239 in words is "twenty million, nine hundred eighty-nine thousand, two hundred thirty-nine".