1312041221 has 4 divisors (see below), whose sum is σ = 1312269612. Its totient is φ = 1311812832.

The previous prime is 1312041217. The next prime is 1312041223. The reversal of 1312041221 is 1221402131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221402131 = 21991 ⋅55541.

It can be written as a sum of positive squares in 2 ways, for example, as 1016716996 + 295324225 = 31886^2 + 17185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312041221 - 2² = 1312041217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1312041221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312041223) 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, 105350 + ... + 117143.

It is an arithmetic number, because the mean of its divisors is an integer number (328067403).

Almost surely, 2^1312041221 is an apocalyptic number.

It is an amenable number.

1312041221 is a deficient number, since it is larger than the sum of its proper divisors (228391).

1312041221 is an equidigital number, since it uses as much as digits as its factorization.

1312041221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228390.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1312041221 is about 36222.1095603224. The cubic root of 1312041221 is about 1094.7521998569.

Adding to 1312041221 its reverse (1221402131), we get a palindrome (2533443352).

The spelling of 1312041221 in words is "one billion, three hundred twelve million, forty-one thousand, two hundred twenty-one".