21625044 has 48 divisors (see below), whose sum is σ = 59017728. Its totient is φ = 6033888.

The previous prime is 21625033. The next prime is 21625061. The reversal of 21625044 is 44052612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 619 + ... + 6605.

It is an arithmetic number, because the mean of its divisors is an integer number (1229536).

Almost surely, 2^21625044 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 21625044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29508864).

21625044 is an abundant number, since it is smaller than the sum of its proper divisors (37392684).

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

21625044 is a wasteful number, since it uses less digits than its factorization.

21625044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6044 (or 6042 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 21625044 is about 4650.2735403415. The cubic root of 21625044 is about 278.6029217330.

Adding to 21625044 its reverse (44052612), we get a palindrome (65677656).

The spelling of 21625044 in words is "twenty-one million, six hundred twenty-five thousand, forty-four".