21744044 has 18 divisors (see below), whose sum is σ = 44265060. Its totient is φ = 9318792.

The previous prime is 21744043. The next prime is 21744089. The reversal of 21744044 is 44044712.

21744044 = 642² + 643² + ... + 690².

It is not an unprimeable number, because it can be changed into a prime (21744043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55274 + ... + 55665.

It is an arithmetic number, because the mean of its divisors is an integer number (2459170).

Almost surely, 2^21744044 is an apocalyptic number.

It is an amenable number.

21744044 is an abundant number, since it is smaller than the sum of its proper divisors (22521016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21744044 is a wasteful number, since it uses less digits than its factorization.

21744044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110957 (or 110948 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 26.

The square root of 21744044 is about 4663.0509325977. The cubic root of 21744044 is about 279.1130265793.

Adding to 21744044 its reverse (44044712), we get a palindrome (65788756).

The spelling of 21744044 in words is "twenty-one million, seven hundred forty-four thousand, forty-four".