11221131231 has 64 divisors (see below), whose sum is σ = 18273116160. Its totient is φ = 6777146880.

The previous prime is 11221131203. The next prime is 11221131253. The reversal of 11221131231 is 13213112211.

11221131231 is a `hidden beast` number, since 112 + 211 + 312 + 31 = 666.

It is not a de Polignac number, because 11221131231 - 2⁵ = 11221131199 is a prime.

It is a super-2 number, since 2×11221131231² (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 (11221131731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1311690 + ... + 1320216.

It is an arithmetic number, because the mean of its divisors is an integer number (285517440).

Almost surely, 2^11221131231 is an apocalyptic number.

11221131231 is a deficient number, since it is larger than the sum of its proper divisors (7051984929).

11221131231 is a wasteful number, since it uses less digits than its factorization.

11221131231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8661 (or 8655 counting only the distinct ones).

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

Adding to 11221131231 its reverse (13213112211), we get a palindrome (24434243442).

The spelling of 11221131231 in words is "eleven billion, two hundred twenty-one million, one hundred thirty-one thousand, two hundred thirty-one".