21333331121 has 4 divisors (see below), whose sum is σ = 21334190592. Its totient is φ = 21332471652.

The previous prime is 21333331111. The next prime is 21333331177. The reversal of 21333331121 is 12113333312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21333331121 - 2²² = 21329136817 is a prime.

It is a super-2 number, since 2×21333331121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21333331111) 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, 391361 + ... + 442526.

It is an arithmetic number, because the mean of its divisors is an integer number (5333547648).

Almost surely, 2^21333331121 is an apocalyptic number.

It is an amenable number.

21333331121 is a deficient number, since it is larger than the sum of its proper divisors (859471).

21333331121 is an equidigital number, since it uses as much as digits as its factorization.

21333331121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859470.

The product of its digits is 972, while the sum is 23.

Adding to 21333331121 its reverse (12113333312), we get a palindrome (33446664433).

The spelling of 21333331121 in words is "twenty-one billion, three hundred thirty-three million, three hundred thirty-one thousand, one hundred twenty-one".