21245252 has 24 divisors (see below), whose sum is σ = 43641024. Its totient is φ = 8858592.

The previous prime is 21245227. The next prime is 21245281. The reversal of 21245252 is 25254212.

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, 9218 + ... + 11289.

It is an arithmetic number, because the mean of its divisors is an integer number (1818376).

Almost surely, 2^21245252 is an apocalyptic number.

It is an amenable number.

21245252 is an abundant number, since it is smaller than the sum of its proper divisors (22395772).

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

21245252 is a wasteful number, since it uses less digits than its factorization.

21245252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20555 (or 20553 counting only the distinct ones).

The product of its digits is 1600, while the sum is 23.

The square root of 21245252 is about 4609.2572069695. The cubic root of 21245252 is about 276.9622820482.

Adding to 21245252 its reverse (25254212), we get a palindrome (46499464).

The spelling of 21245252 in words is "twenty-one million, two hundred forty-five thousand, two hundred fifty-two".