21622239 has 12 divisors (see below), whose sum is σ = 31525416. Its totient is φ = 14279472.

The previous prime is 21622219. The next prime is 21622241. The reversal of 21622239 is 93222612.

21622239 is a `hidden beast` number, since 2 + 1 + 622 + 2 + 39 = 666.

It is not a de Polignac number, because 21622239 - 2¹⁵ = 21589471 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21622219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10264 + ... + 12189.

It is an arithmetic number, because the mean of its divisors is an integer number (2627118).

Almost surely, 2^21622239 is an apocalyptic number.

21622239 is a deficient number, since it is larger than the sum of its proper divisors (9903177).

21622239 is a wasteful number, since it uses less digits than its factorization.

21622239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22566 (or 22563 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 21622239 is about 4649.9719353992. The cubic root of 21622239 is about 278.5908752837.

The spelling of 21622239 in words is "twenty-one million, six hundred twenty-two thousand, two hundred thirty-nine".