21331131311 has 4 divisors (see below), whose sum is σ = 24378435792. Its totient is φ = 18283826832.

The previous prime is 21331131271. The next prime is 21331131323. The reversal of 21331131311 is 11313113312.

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-21331131311 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 (21331131011) 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, 1523652230 + ... + 1523652243.

It is an arithmetic number, because the mean of its divisors is an integer number (6094608948).

Almost surely, 2^21331131311 is an apocalyptic number.

21331131311 is a deficient number, since it is larger than the sum of its proper divisors (3047304481).

21331131311 is an equidigital number, since it uses as much as digits as its factorization.

21331131311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3047304480.

The product of its digits is 162, while the sum is 20.

Adding to 21331131311 its reverse (11313113312), we get a palindrome (32644244623).

The spelling of 21331131311 in words is "twenty-one billion, three hundred thirty-one million, one hundred thirty-one thousand, three hundred eleven".