21233121311 has 4 divisors (see below), whose sum is σ = 21233446224. Its totient is φ = 21232796400.

The previous prime is 21233121289. The next prime is 21233121361. The reversal of 21233121311 is 11312133212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21233121311 - 2¹⁴ = 21233104927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233121361) 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, 26510 + ... + 207771.

It is an arithmetic number, because the mean of its divisors is an integer number (5308361556).

Almost surely, 2^21233121311 is an apocalyptic number.

21233121311 is a deficient number, since it is larger than the sum of its proper divisors (324913).

21233121311 is an equidigital number, since it uses as much as digits as its factorization.

21233121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324912.

The product of its digits is 216, while the sum is 20.

Adding to 21233121311 its reverse (11312133212), we get a palindrome (32545254523).

It can be divided in two parts, 21 and 233121311, that added together give a palindrome (233121332).

The spelling of 21233121311 in words is "twenty-one billion, two hundred thirty-three million, one hundred twenty-one thousand, three hundred eleven".