21223131331 has 4 divisors (see below), whose sum is σ = 21302028000. Its totient is φ = 21144234664.

The previous prime is 21223131301. The next prime is 21223131337. The reversal of 21223131331 is 13313132212.

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 21223131331 - 2¹⁵ = 21223098563 is a prime.

It is a super-2 number, since 2×21223131331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21223131337) 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, 39447931 + ... + 39448468.

It is an arithmetic number, because the mean of its divisors is an integer number (5325507000).

Almost surely, 2^21223131331 is an apocalyptic number.

21223131331 is a deficient number, since it is larger than the sum of its proper divisors (78896669).

21223131331 is an equidigital number, since it uses as much as digits as its factorization.

21223131331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78896668.

The product of its digits is 648, while the sum is 22.

Adding to 21223131331 its reverse (13313132212), we get a palindrome (34536263543).

The spelling of 21223131331 in words is "twenty-one billion, two hundred twenty-three million, one hundred thirty-one thousand, three hundred thirty-one".