21333320 has 32 divisors (see below), whose sum is σ = 48220920. Its totient is φ = 8494080.

The previous prime is 21333271. The next prime is 21333329. The reversal of 21333320 is 2333312.

It can be written as a sum of positive squares in 4 ways, for example, as 21325924 + 7396 = 4618^2 + 86^2 .

It is a super-2 number, since 2×21333320² = 910221084444800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21333329) 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, 8534 + ... + 10746.

Almost surely, 2^21333320 is an apocalyptic number.

21333320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21333320 is an abundant number, since it is smaller than the sum of its proper divisors (26887600).

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

21333320 is a wasteful number, since it uses less digits than its factorization.

21333320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2465 (or 2461 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 17.

The square root of 21333320 is about 4618.8007101411. The cubic root of 21333320 is about 277.3444519601.

Adding to 21333320 its reverse (2333312), we get a palindrome (23666632).

It can be divided in two parts, 213 and 33320, that added together give a palindrome (33533).

The spelling of 21333320 in words is "twenty-one million, three hundred thirty-three thousand, three hundred twenty".