21052444 has 24 divisors (see below), whose sum is σ = 42381920. Its totient is φ = 8963136.

The previous prime is 21052411. The next prime is 21052469. The reversal of 21052444 is 44425012.

It is a happy number.

It is a congruent number.

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, 2002 + ... + 6790.

Almost surely, 2^21052444 is an apocalyptic number.

It is an amenable number.

21052444 is an abundant number, since it is smaller than the sum of its proper divisors (21329476).

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

21052444 is a wasteful number, since it uses less digits than its factorization.

21052444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4957 (or 4955 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 21052444 is about 4588.2942364238. The cubic root of 21052444 is about 276.1218918298.

Adding to 21052444 its reverse (44425012), we get a palindrome (65477456).

The spelling of 21052444 in words is "twenty-one million, fifty-two thousand, four hundred forty-four".