11111121231 has 16 divisors (see below), whose sum is σ = 16934476800. Its totient is φ = 6347995488.

The previous prime is 11111121211. The next prime is 11111121247. The reversal of 11111121231 is 13212111111.

It is not a de Polignac number, because 11111121231 - 2¹¹ = 11111119183 is a prime.

It is a super-2 number, since 2×11111121231² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11111121231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111121211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67965 + ... + 163833.

It is an arithmetic number, because the mean of its divisors is an integer number (1058404800).

Almost surely, 2^11111121231 is an apocalyptic number.

11111121231 is a deficient number, since it is larger than the sum of its proper divisors (5823355569).

11111121231 is an equidigital number, since it uses as much as digits as its factorization.

11111121231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101398.

The product of its digits is 12, while the sum is 15.

Adding to 11111121231 its reverse (13212111111), we get a palindrome (24323232342).

The spelling of 11111121231 in words is "eleven billion, one hundred eleven million, one hundred twenty-one thousand, two hundred thirty-one".