1231113221 has 4 divisors (see below), whose sum is σ = 1325814252. Its totient is φ = 1136412192.

The previous prime is 1231113211. The next prime is 1231113251. The reversal of 1231113221 is 1223111321.

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 522808225 + 708304996 = 22865^2 + 26614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231113221 - 2²⁶ = 1164004357 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231113221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231113211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47350496 + ... + 47350521.

It is an arithmetic number, because the mean of its divisors is an integer number (331453563).

Almost surely, 2^1231113221 is an apocalyptic number.

It is an amenable number.

1231113221 is a deficient number, since it is larger than the sum of its proper divisors (94701031).

1231113221 is an equidigital number, since it uses as much as digits as its factorization.

1231113221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94701030.

The product of its digits is 72, while the sum is 17.

The square root of 1231113221 is about 35087.2230448635. The cubic root of 1231113221 is about 1071.7644109554.

Adding to 1231113221 its reverse (1223111321), we get a palindrome (2454224542).

The spelling of 1231113221 in words is "one billion, two hundred thirty-one million, one hundred thirteen thousand, two hundred twenty-one".