12111213231 has 20 divisors (see below), whose sum is σ = 19483757832. Its totient is φ = 7453053648.

The previous prime is 12111213229. The next prime is 12111213239. The reversal of 12111213231 is 13231211121.

It is not a de Polignac number, because 12111213231 - 2¹ = 12111213229 is a prime.

It is a super-2 number, since 2×12111213231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111213239) 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 19 ways as a sum of consecutive naturals, for example, 5749761 + ... + 5751866.

Almost surely, 2^12111213231 is an apocalyptic number.

12111213231 is a deficient number, since it is larger than the sum of its proper divisors (7372544601).

12111213231 is a wasteful number, since it uses less digits than its factorization.

12111213231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11501652 (or 11501643 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 12111213231 its reverse (13231211121), we get a palindrome (25342424352).

The spelling of 12111213231 in words is "twelve billion, one hundred eleven million, two hundred thirteen thousand, two hundred thirty-one".