21302232 has 128 divisors (see below), whose sum is σ = 65664000. Its totient is φ = 5626368.

The previous prime is 21302227. The next prime is 21302251. The reversal of 21302232 is 23220312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142894 + ... + 143042.

It is an arithmetic number, because the mean of its divisors is an integer number (513000).

Almost surely, 2^21302232 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 21302232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32832000).

21302232 is an abundant number, since it is smaller than the sum of its proper divisors (44361768).

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

21302232 is a wasteful number, since it uses less digits than its factorization.

21302232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21302232 is about 4615.4341074269. The cubic root of 21302232 is about 277.2096663150.

Adding to 21302232 its reverse (23220312), we get a palindrome (44522544).

It can be divided in two parts, 21 and 302232, that added together give a triangular number (302253 = T₇₇₇).

The spelling of 21302232 in words is "twenty-one million, three hundred two thousand, two hundred thirty-two".