21233311331 has 4 divisors (see below), whose sum is σ = 21581398464. Its totient is φ = 20885224200.

The previous prime is 21233311303. The next prime is 21233311361. The reversal of 21233311331 is 13311333212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21233311331 is a prime.

It is a super-2 number, since 2×21233311331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21233311297 and 21233311306.

It is not an unprimeable number, because it can be changed into a prime (21233311361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174043475 + ... + 174043596.

It is an arithmetic number, because the mean of its divisors is an integer number (5395349616).

Almost surely, 2^21233311331 is an apocalyptic number.

21233311331 is a deficient number, since it is larger than the sum of its proper divisors (348087133).

21233311331 is an equidigital number, since it uses as much as digits as its factorization.

21233311331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348087132.

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

Adding to 21233311331 its reverse (13311333212), we get a palindrome (34544644543).

The spelling of 21233311331 in words is "twenty-one billion, two hundred thirty-three million, three hundred eleven thousand, three hundred thirty-one".