21744219 has 16 divisors (see below), whose sum is σ = 33447168. Its totient is φ = 12307872.

The previous prime is 21744209. The next prime is 21744253. The reversal of 21744219 is 91244712.

It is not a de Polignac number, because 21744219 - 2¹⁵ = 21711451 is a prime.

It is a super-2 number, since 2×21744219² = 945622119839922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21744209) 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, 2592 + ... + 7085.

It is an arithmetic number, because the mean of its divisors is an integer number (2090448).

Almost surely, 2^21744219 is an apocalyptic number.

21744219 is a deficient number, since it is larger than the sum of its proper divisors (11702949).

21744219 is a wasteful number, since it uses less digits than its factorization.

21744219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9794.

The product of its digits is 4032, while the sum is 30.

The square root of 21744219 is about 4663.0696970987. The cubic root of 21744219 is about 279.1137753613.

The spelling of 21744219 in words is "twenty-one million, seven hundred forty-four thousand, two hundred nineteen".