21488444 has 12 divisors (see below), whose sum is σ = 37770600. Its totient is φ = 10696848.

The previous prime is 21488431. The next prime is 21488477. The reversal of 21488444 is 44488412.

It is a super-2 number, since 2×21488444² = 923506451082272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10814 + ... + 12645.

It is an arithmetic number, because the mean of its divisors is an integer number (3147550).

Almost surely, 2^21488444 is an apocalyptic number.

It is an amenable number.

21488444 is a deficient number, since it is larger than the sum of its proper divisors (16282156).

21488444 is a wasteful number, since it uses less digits than its factorization.

21488444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23692 (or 23690 counting only the distinct ones).

The product of its digits is 32768, while the sum is 35.

The square root of 21488444 is about 4635.5629647325. The cubic root of 21488444 is about 278.0150605163.

The spelling of 21488444 in words is "twenty-one million, four hundred eighty-eight thousand, four hundred forty-four".