21844497 has 16 divisors (see below), whose sum is σ = 29641472. Its totient is φ = 14307840.

The previous prime is 21844489. The next prime is 21844531. The reversal of 21844497 is 79444812.

It is not a de Polignac number, because 21844497 - 2³ = 21844489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21844297) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78723 + ... + 78999.

It is an arithmetic number, because the mean of its divisors is an integer number (1852592).

Almost surely, 2^21844497 is an apocalyptic number.

It is an amenable number.

21844497 is a deficient number, since it is larger than the sum of its proper divisors (7796975).

21844497 is a wasteful number, since it uses less digits than its factorization.

21844497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648.

The product of its digits is 64512, while the sum is 39.

The square root of 21844497 is about 4673.8096880382. The cubic root of 21844497 is about 279.5421812655.

The spelling of 21844497 in words is "twenty-one million, eight hundred forty-four thousand, four hundred ninety-seven".