1213112311 has 4 divisors (see below), whose sum is σ = 1254943800. Its totient is φ = 1171280824.

The previous prime is 1213112309. The next prime is 1213112317. The reversal of 1213112311 is 1132113121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1132113121 = 3631 ⋅311791.

It is a cyclic number.

It is not a de Polignac number, because 1213112311 - 2¹ = 1213112309 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 (1213112317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20915701 + ... + 20915758.

It is an arithmetic number, because the mean of its divisors is an integer number (313735950).

Almost surely, 2^1213112311 is an apocalyptic number.

1213112311 is a deficient number, since it is larger than the sum of its proper divisors (41831489).

1213112311 is an equidigital number, since it uses as much as digits as its factorization.

1213112311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41831488.

The product of its digits is 36, while the sum is 16.

The square root of 1213112311 is about 34829.7618567799. The cubic root of 1213112311 is about 1066.5150869350.

Adding to 1213112311 its reverse (1132113121), we get a palindrome (2345225432).

It can be divided in two parts, 12131 and 12311, that added together give a palindrome (24442).

The spelling of 1213112311 in words is "one billion, two hundred thirteen million, one hundred twelve thousand, three hundred eleven".