21659444 has 12 divisors (see below), whose sum is σ = 38785824. Its totient is φ = 10577784.

The previous prime is 21659441. The next prime is 21659459. The reversal of 21659444 is 44495612.

It is a hoax number, since the sum of its digits (35) 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 (21659441) 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, 62792 + ... + 63135.

It is an arithmetic number, because the mean of its divisors is an integer number (3232152).

Almost surely, 2^21659444 is an apocalyptic number.

It is an amenable number.

21659444 is a deficient number, since it is larger than the sum of its proper divisors (17126380).

21659444 is a wasteful number, since it uses less digits than its factorization.

21659444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125974 (or 125972 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 21659444 is about 4653.9707777338. The cubic root of 21659444 is about 278.7505725018.

The spelling of 21659444 in words is "twenty-one million, six hundred fifty-nine thousand, four hundred forty-four".