1231220223121 has 12 divisors (see below), whose sum is σ = 1478436925440. Its totient is φ = 1021288663080.

The previous prime is 1231220223109. The next prime is 1231220223137. The reversal of 1231220223121 is 1213220221321.

It is not a de Polignac number, because 1231220223121 - 2¹⁵ = 1231220190353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231220223092 and 1231220223101.

It is not an unprimeable number, because it can be changed into a prime (1231220223161) 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, 405271761 + ... + 405274798.

It is an arithmetic number, because the mean of its divisors is an integer number (123203077120).

Almost surely, 2^{1231220223121} is an apocalyptic number.

It is an amenable number.

1231220223121 is a deficient number, since it is larger than the sum of its proper divisors (247216702319).

1231220223121 is an equidigital number, since it uses as much as digits as its factorization.

1231220223121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810546604 (or 810546597 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 1231220223121 its reverse (1213220221321), we get a palindrome (2444440444442).

The spelling of 1231220223121 in words is "one trillion, two hundred thirty-one billion, two hundred twenty million, two hundred twenty-three thousand, one hundred twenty-one".