1231213113 has 12 divisors (see below), whose sum is σ = 1915220580. Its totient is φ = 757669536.

The previous prime is 1231213103. The next prime is 1231213127. The reversal of 1231213113 is 3113121321.

It can be written as a sum of positive squares in 2 ways, for example, as 187470864 + 1043742249 = 13692^2 + 32307^2 .

It is not a de Polignac number, because 1231213113 - 2⁹ = 1231212601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231213103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5261478 + ... + 5261711.

It is an arithmetic number, because the mean of its divisors is an integer number (159601715).

Almost surely, 2^1231213113 is an apocalyptic number.

1231213113 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1231213113 is a deficient number, since it is larger than the sum of its proper divisors (684007467).

1231213113 is a wasteful number, since it uses less digits than its factorization.

1231213113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10523208 (or 10523205 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 1231213113 is about 35088.6464971221. The cubic root of 1231213113 is about 1071.7933976733.

Adding to 1231213113 its reverse (3113121321), we get a palindrome (4344334434).

It can be divided in two parts, 12312 and 13113, that added together give a triangular number (25425 = T₂₂₅).

The spelling of 1231213113 in words is "one billion, two hundred thirty-one million, two hundred thirteen thousand, one hundred thirteen".