21333020 has 12 divisors (see below), whose sum is σ = 44799384. Its totient is φ = 8533200.

The previous prime is 21333019. The next prime is 21333023. The reversal of 21333020 is 2033312.

It is a junction number, because it is equal to n+sod(n) for n = 21332986 and 21333004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533306 + ... + 533345.

It is an arithmetic number, because the mean of its divisors is an integer number (3733282).

Almost surely, 2^21333020 is an apocalyptic number.

21333020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21333020 is an abundant number, since it is smaller than the sum of its proper divisors (23466364).

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

21333020 is a wasteful number, since it uses less digits than its factorization.

21333020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066660 (or 1066658 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 14.

The square root of 21333020 is about 4618.7682340641. The cubic root of 21333020 is about 277.3431519011.

Adding to 21333020 its reverse (2033312), we get a palindrome (23366332).

It can be divided in two parts, 213 and 33020, that added together give a palindrome (33233).

The spelling of 21333020 in words is "twenty-one million, three hundred thirty-three thousand, twenty".