21544144 has 20 divisors (see below), whose sum is σ = 42247296. Its totient is φ = 10641632.

The previous prime is 21544139. The next prime is 21544181. The reversal of 21544144 is 44144512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6784 + ... + 9439.

Almost surely, 2^21544144 is an apocalyptic number.

It is an amenable number.

21544144 is a deficient number, since it is larger than the sum of its proper divisors (20703152).

21544144 is a wasteful number, since it uses less digits than its factorization.

21544144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16314 (or 16308 counting only the distinct ones).

The product of its digits is 2560, while the sum is 25.

The square root of 21544144 is about 4641.5669767870. The cubic root of 21544144 is about 278.2550666985.

Adding to 21544144 its reverse (44144512), we get a palindrome (65688656).

The spelling of 21544144 in words is "twenty-one million, five hundred forty-four thousand, one hundred forty-four".