1312544221 has 4 divisors (see below), whose sum is σ = 1318177692. Its totient is φ = 1306910752.

The previous prime is 1312544213. The next prime is 1312544227. The reversal of 1312544221 is 1224452131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 355322500 + 957221721 = 18850^2 + 30939^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312544221 - 2³ = 1312544213 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 (1312544227) 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, 2816386 + ... + 2816851.

It is an arithmetic number, because the mean of its divisors is an integer number (329544423).

Almost surely, 2^1312544221 is an apocalyptic number.

It is an amenable number.

1312544221 is a deficient number, since it is larger than the sum of its proper divisors (5633471).

1312544221 is an equidigital number, since it uses as much as digits as its factorization.

1312544221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5633470.

The product of its digits is 1920, while the sum is 25.

The square root of 1312544221 is about 36229.0521681150. The cubic root of 1312544221 is about 1094.8920811333.

Adding to 1312544221 its reverse (1224452131), we get a palindrome (2536996352).

The spelling of 1312544221 in words is "one billion, three hundred twelve million, five hundred forty-four thousand, two hundred twenty-one".