21333121 has 8 divisors (see below), whose sum is σ = 22310784. Its totient is φ = 20359680.

The previous prime is 21333107. The next prime is 21333133. The reversal of 21333121 is 12133312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21333121 - 2⁵ = 21333089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21333095 and 21333104.

It is not an unprimeable number, because it can be changed into a prime (21033121) 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, 14020 + ... + 15466.

It is an arithmetic number, because the mean of its divisors is an integer number (2788848).

Almost surely, 2^21333121 is an apocalyptic number.

It is an amenable number.

21333121 is a deficient number, since it is larger than the sum of its proper divisors (977663).

21333121 is a wasteful number, since it uses less digits than its factorization.

21333121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2111.

The product of its digits is 108, while the sum is 16.

The square root of 21333121 is about 4618.7791677022. The cubic root of 21333121 is about 277.3435895890.

Adding to 21333121 its reverse (12133312), we get a palindrome (33466433).

The spelling of 21333121 in words is "twenty-one million, three hundred thirty-three thousand, one hundred twenty-one".