21074944 has 44 divisors (see below), whose sum is σ = 45983808. Its totient is φ = 9574400.

The previous prime is 21074939. The next prime is 21074957. The reversal of 21074944 is 44947012.

It is a tau number, because it is divible by the number of its divisors (44).

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, 10329 + ... + 12199.

Almost surely, 2^21074944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21074944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22991904).

21074944 is an abundant number, since it is smaller than the sum of its proper divisors (24908864).

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

21074944 is a wasteful number, since it uses less digits than its factorization.

21074944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1902 (or 1884 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21074944 is about 4590.7454732320. The cubic root of 21074944 is about 276.2202261067.

The spelling of 21074944 in words is "twenty-one million, seventy-four thousand, nine hundred forty-four".