1312231121221 has 4 divisors (see below), whose sum is σ = 1312260868000. Its totient is φ = 1312201374444.

The previous prime is 1312231121209. The next prime is 1312231121237. The reversal of 1312231121221 is 1221211322131.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1312231121221 - 2²⁹ = 1311694250309 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1312231121192 and 1312231121201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312231121281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14807121 + ... + 14895478.

It is an arithmetic number, because the mean of its divisors is an integer number (328065217000).

Almost surely, 2^{1312231121221} is an apocalyptic number.

It is an amenable number.

1312231121221 is a deficient number, since it is larger than the sum of its proper divisors (29746779).

1312231121221 is an equidigital number, since it uses as much as digits as its factorization.

1312231121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29746778.

The product of its digits is 288, while the sum is 22.

Adding to 1312231121221 its reverse (1221211322131), we get a palindrome (2533442443352).

The spelling of 1312231121221 in words is "one trillion, three hundred twelve billion, two hundred thirty-one million, one hundred twenty-one thousand, two hundred twenty-one".