21331111211231 has 4 divisors (see below), whose sum is σ = 22453801275000. Its totient is φ = 20208421147464.

The previous prime is 21331111211227. The next prime is 21331111211281. The reversal of 21331111211231 is 13211211113312.

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 21331111211231 - 2² = 21331111211227 is a prime.

It is a super-2 number, since 2×21331111211231² (a number of 27 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 = 21331111211197 and 21331111211206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331111211281) 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, 561345031856 + ... + 561345031893.

It is an arithmetic number, because the mean of its divisors is an integer number (5613450318750).

Almost surely, 2^{21331111211231} is an apocalyptic number.

21331111211231 is a deficient number, since it is larger than the sum of its proper divisors (1122690063769).

21331111211231 is a wasteful number, since it uses less digits than its factorization.

21331111211231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122690063768.

The product of its digits is 216, while the sum is 23.

Adding to 21331111211231 its reverse (13211211113312), we get a palindrome (34542322324543).

The spelling of 21331111211231 in words is "twenty-one trillion, three hundred thirty-one billion, one hundred eleven million, two hundred eleven thousand, two hundred thirty-one".