21600252 has 36 divisors (see below), whose sum is σ = 55266120. Its totient is φ = 7112352.

The previous prime is 21600239. The next prime is 21600263. The reversal of 21600252 is 25200612.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 627 + ... + 6602.

It is an arithmetic number, because the mean of its divisors is an integer number (1535170).

Almost surely, 2^21600252 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 21600252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27633060).

21600252 is an abundant number, since it is smaller than the sum of its proper divisors (33665868).

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

21600252 is a wasteful number, since it uses less digits than its factorization.

21600252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7322 (or 7317 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21600252 is about 4647.6071262533. The cubic root of 21600252 is about 278.4964130499.

Adding to 21600252 its reverse (25200612), we get a palindrome (46800864).

The spelling of 21600252 in words is "twenty-one million, six hundred thousand, two hundred fifty-two".