1231320031111 has 4 divisors (see below), whose sum is σ = 1231322300352. Its totient is φ = 1231317761872.

The previous prime is 1231320031103. The next prime is 1231320031177. The reversal of 1231320031111 is 1111300231321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1231320031111 - 2³ = 1231320031103 is a prime.

It is a super-2 number, since 2×1231320031111² (a number of 25 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 (1231320041111) 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, 212211 + ... + 1583563.

It is an arithmetic number, because the mean of its divisors is an integer number (307830575088).

Almost surely, 2^{1231320031111} is an apocalyptic number.

1231320031111 is a deficient number, since it is larger than the sum of its proper divisors (2269241).

1231320031111 is an equidigital number, since it uses as much as digits as its factorization.

1231320031111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2269240.

The product of its (nonzero) digits is 108, while the sum is 19.

Adding to 1231320031111 its reverse (1111300231321), we get a palindrome (2342620262432).

The spelling of 1231320031111 in words is "one trillion, two hundred thirty-one billion, three hundred twenty million, thirty-one thousand, one hundred eleven".