11123231231 has 6 divisors (see below), whose sum is σ = 12939269040. Its totient is φ = 9534198156.

The previous prime is 11123231219. The next prime is 11123231267. The reversal of 11123231231 is 13213232111.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-11123231231 is a prime.

It is a super-2 number, since 2×11123231231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11123231281) 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 5 ways as a sum of consecutive naturals, for example, 113502311 + ... + 113502408.

It is an arithmetic number, because the mean of its divisors is an integer number (2156544840).

Almost surely, 2^11123231231 is an apocalyptic number.

11123231231 is a deficient number, since it is larger than the sum of its proper divisors (1816037809).

11123231231 is an equidigital number, since it uses as much as digits as its factorization.

11123231231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227004733 (or 227004726 counting only the distinct ones).

The product of its digits is 216, while the sum is 20.

Adding to 11123231231 its reverse (13213232111), we get a palindrome (24336463342).

The spelling of 11123231231 in words is "eleven billion, one hundred twenty-three million, two hundred thirty-one thousand, two hundred thirty-one".