11123231213 has 4 divisors (see below), whose sum is σ = 11506790940.
Its totient is φ = 10739671488.
The previous prime is 11123231209. The next prime is 11123231219. The reversal of 11123231213 is 31213232111.
It is a happy number.
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 5975599204 + 5147632009 = 77302^2 + 71747^2
It is a cyclic number.
It is not a de Polignac number, because 11123231213 - 22 = 11123231209 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (11123231219) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191779820 + ... + 191779877.
It is an arithmetic number, because the mean of its divisors is an integer number (2876697735).
Almost surely, 211123231213 is an apocalyptic number.
It is an amenable number.
11123231213 is a deficient number, since it is larger than the sum of its proper divisors (383559727).
11123231213 is an equidigital number, since it uses as much as digits as its factorization.
11123231213 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 383559726.
The product of its digits is 216, while the sum is 20.
Adding to 11123231213 its reverse (31213232111), we get a palindrome (42336463324).
The spelling of 11123231213 in words is "eleven billion, one hundred twenty-three million, two hundred thirty-one thousand, two hundred thirteen".