21335204 has 36 divisors (see below), whose sum is σ = 43470252. Its totient is φ = 9123840.

The previous prime is 21335179. The next prime is 21335207. The reversal of 21335204 is 40253312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14822500 + 6512704 = 3850^2 + 2552^2 .

It is not an unprimeable number, because it can be changed into a prime (21335207) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6932 + ... + 9524.

It is an arithmetic number, because the mean of its divisors is an integer number (1207507).

Almost surely, 2^21335204 is an apocalyptic number.

It is an amenable number.

21335204 is an abundant number, since it is smaller than the sum of its proper divisors (22135048).

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

21335204 is a wasteful number, since it uses less digits than its factorization.

21335204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636 (or 2623 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 21335204 is about 4619.0046546848. The cubic root of 21335204 is about 277.3526160522.

Adding to 21335204 its reverse (40253312), we get a palindrome (61588516).

It can be divided in two parts, 2133 and 5204, that added together give a palindrome (7337).

The spelling of 21335204 in words is "twenty-one million, three hundred thirty-five thousand, two hundred four".