21225336 has 48 divisors (see below), whose sum is σ = 58333800. Its totient is φ = 6431040.

The previous prime is 21225329. The next prime is 21225349. The reversal of 21225336 is 63352212.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 751 + ... + 6558.

Almost surely, 2^21225336 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 21225336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29166900).

21225336 is an abundant number, since it is smaller than the sum of its proper divisors (37108464).

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

21225336 is a wasteful number, since it uses less digits than its factorization.

21225336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7340 (or 7325 counting only the distinct ones).

The product of its digits is 2160, while the sum is 24.

The square root of 21225336 is about 4607.0962655451. The cubic root of 21225336 is about 276.8757104646.

Adding to 21225336 its reverse (63352212), we get a palindrome (84577548).

The spelling of 21225336 in words is "twenty-one million, two hundred twenty-five thousand, three hundred thirty-six".