21240944 has 20 divisors (see below), whose sum is σ = 41853720. Its totient is φ = 10440000.

The previous prime is 21240913. The next prime is 21240971. The reversal of 21240944 is 44904212.

It is a super-2 number, since 2×21240944² = 902355404022272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

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, 10307 + ... + 12194.

It is an arithmetic number, because the mean of its divisors is an integer number (2092686).

Almost surely, 2^21240944 is an apocalyptic number.

It is an amenable number.

21240944 is a deficient number, since it is larger than the sum of its proper divisors (20612776).

21240944 is a wasteful number, since it uses less digits than its factorization.

21240944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22568 (or 22562 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21240944 is about 4608.7898628599. The cubic root of 21240944 is about 276.9435604665.

The spelling of 21240944 in words is "twenty-one million, two hundred forty thousand, nine hundred forty-four".