21245444 has 24 divisors (see below), whose sum is σ = 42946848. Its totient is φ = 9088640.

The previous prime is 21245417. The next prime is 21245459. The reversal of 21245444 is 44454212.

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, 13454 + ... + 14949.

It is an arithmetic number, because the mean of its divisors is an integer number (1789452).

Almost surely, 2^21245444 is an apocalyptic number.

It is an amenable number.

21245444 is an abundant number, since it is smaller than the sum of its proper divisors (21701404).

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

21245444 is a wasteful number, since it uses less digits than its factorization.

21245444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28435 (or 28433 counting only the distinct ones).

The product of its digits is 5120, while the sum is 26.

The square root of 21245444 is about 4609.2780345733. The cubic root of 21245444 is about 276.9631163774.

Adding to 21245444 its reverse (44454212), we get a palindrome (65699656).

The spelling of 21245444 in words is "twenty-one million, two hundred forty-five thousand, four hundred forty-four".