11121312231 has 24 divisors (see below), whose sum is σ = 16664035024. Its totient is φ = 7412005440.

The previous prime is 11121312211. The next prime is 11121312247. The reversal of 11121312231 is 13221312111.

11121312231 is a `hidden beast` number, since 1 + 1 + 121 + 312 + 231 = 666.

It is not a de Polignac number, because 11121312231 - 2¹⁰ = 11121311207 is a prime.

It is a super-2 number, since 2×11121312231² (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 (11121312211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1483665 + ... + 1491141.

Almost surely, 2^11121312231 is an apocalyptic number.

11121312231 is a deficient number, since it is larger than the sum of its proper divisors (5542722793).

11121312231 is an frugal number, since it uses more digits than its factorization.

11121312231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13613 (or 13601 counting only the distinct ones).

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

Adding to 11121312231 its reverse (13221312111), we get a palindrome (24342624342).

The spelling of 11121312231 in words is "eleven billion, one hundred twenty-one million, three hundred twelve thousand, two hundred thirty-one".