21238239 has 8 divisors (see below), whose sum is σ = 30892032. Its totient is φ = 12871640.

The previous prime is 21238229. The next prime is 21238249. The reversal of 21238239 is 93283212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21238229) and next prime (21238249).

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

It is a cyclic number.

It is not a de Polignac number, because 21238239 - 2⁵ = 21238207 is a prime.

It is a super-2 number, since 2×21238239² = 902125591642242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21238229) 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, 321759 + ... + 321824.

It is an arithmetic number, because the mean of its divisors is an integer number (3861504).

Almost surely, 2^21238239 is an apocalyptic number.

21238239 is a deficient number, since it is larger than the sum of its proper divisors (9653793).

21238239 is a wasteful number, since it uses less digits than its factorization.

21238239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643597.

The product of its digits is 5184, while the sum is 30.

The square root of 21238239 is about 4608.4963925341. The cubic root of 21238239 is about 276.9318038620.

The spelling of 21238239 in words is "twenty-one million, two hundred thirty-eight thousand, two hundred thirty-nine".