21358444 has 24 divisors (see below), whose sum is σ = 39916800. Its totient is φ = 9975504.

The previous prime is 21358439. The next prime is 21358453. The reversal of 21358444 is 44485312.

It is a super-2 number, since 2×21358444² = 912366260202272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1257 + ... + 6655.

It is an arithmetic number, because the mean of its divisors is an integer number (1663200).

Almost surely, 2^21358444 is an apocalyptic number.

It is an amenable number.

21358444 is a deficient number, since it is larger than the sum of its proper divisors (18558356).

21358444 is a wasteful number, since it uses less digits than its factorization.

21358444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5469 (or 5467 counting only the distinct ones).

The product of its digits is 15360, while the sum is 31.

The square root of 21358444 is about 4621.5196634873. The cubic root of 21358444 is about 277.4532843472.

The spelling of 21358444 in words is "twenty-one million, three hundred fifty-eight thousand, four hundred forty-four".