21044252 has 6 divisors (see below), whose sum is σ = 36827448. Its totient is φ = 10522124.

The previous prime is 21044251. The next prime is 21044263. The reversal of 21044252 is 25244012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2630528 + ... + 2630535.

It is an arithmetic number, because the mean of its divisors is an integer number (6137908).

Almost surely, 2^21044252 is an apocalyptic number.

It is an amenable number.

21044252 is a deficient number, since it is larger than the sum of its proper divisors (15783196).

21044252 is a wasteful number, since it uses less digits than its factorization.

21044252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5261067 (or 5261065 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 21044252 is about 4587.4014430830. The cubic root of 21044252 is about 276.0860720140.

Adding to 21044252 its reverse (25244012), we get a palindrome (46288264).

The spelling of 21044252 in words is "twenty-one million, forty-four thousand, two hundred fifty-two".