21238844 has 48 divisors (see below), whose sum is σ = 43739136. Its totient is φ = 8923200.

The previous prime is 21238843. The next prime is 21238859. The reversal of 21238844 is 44883212.

It is a self number, because there is not a number n which added to its sum of digits gives 21238844.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21238843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31034 + ... + 31710.

It is an arithmetic number, because the mean of its divisors is an integer number (911232).

Almost surely, 2^21238844 is an apocalyptic number.

It is an amenable number.

21238844 is an abundant number, since it is smaller than the sum of its proper divisors (22500292).

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

21238844 is a wasteful number, since it uses less digits than its factorization.

21238844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 744 counting only the distinct ones).

The product of its digits is 12288, while the sum is 32.

The square root of 21238844 is about 4608.5620316971. The cubic root of 21238844 is about 276.9344334295.

The spelling of 21238844 in words is "twenty-one million, two hundred thirty-eight thousand, eight hundred forty-four".