21759252 has 24 divisors (see below), whose sum is σ = 53758656. Its totient is φ = 6826368.

The previous prime is 21759229. The next prime is 21759253. The reversal of 21759252 is 25295712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21759253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53128 + ... + 53535.

It is an arithmetic number, because the mean of its divisors is an integer number (2239944).

Almost surely, 2^21759252 is an apocalyptic number.

It is an amenable number.

21759252 is an abundant number, since it is smaller than the sum of its proper divisors (31999404).

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

21759252 is a wasteful number, since it uses less digits than its factorization.

21759252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106687 (or 106685 counting only the distinct ones).

The product of its digits is 12600, while the sum is 33.

The square root of 21759252 is about 4664.6813395987. The cubic root of 21759252 is about 279.1780828875.

The spelling of 21759252 in words is "twenty-one million, seven hundred fifty-nine thousand, two hundred fifty-two".