21333760 has 72 divisors (see below), whose sum is σ = 58425696. Its totient is φ = 7311360.

The previous prime is 21333727. The next prime is 21333761. The reversal of 21333760 is 6733312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333761) 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, 7770 + ... + 10150.

It is an arithmetic number, because the mean of its divisors is an integer number (811468).

Almost surely, 2^21333760 is an apocalyptic number.

21333760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21333760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29212848).

21333760 is an abundant number, since it is smaller than the sum of its proper divisors (37091936).

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

21333760 is an equidigital number, since it uses as much as digits as its factorization.

21333760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409 (or 2395 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 25.

The square root of 21333760 is about 4618.8483413076. The cubic root of 21333760 is about 277.3463586913.

The spelling of 21333760 in words is "twenty-one million, three hundred thirty-three thousand, seven hundred sixty".