21333879 has 24 divisors (see below), whose sum is σ = 36435360. Its totient is φ = 11769408.

The previous prime is 21333877. The next prime is 21333881. The reversal of 21333879 is 97833312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21333877) and next prime (21333881).

It is not a de Polignac number, because 21333879 - 2¹ = 21333877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333877) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4012 + ... + 7665.

It is an arithmetic number, because the mean of its divisors is an integer number (1518140).

Almost surely, 2^21333879 is an apocalyptic number.

21333879 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21333879 is a deficient number, since it is larger than the sum of its proper divisors (15101481).

21333879 is a wasteful number, since it uses less digits than its factorization.

21333879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11719 (or 11716 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 21333879 is about 4618.8612232887. The cubic root of 21333879 is about 277.3468743709.

The spelling of 21333879 in words is "twenty-one million, three hundred thirty-three thousand, eight hundred seventy-nine".