1313801221 has 4 divisors (see below), whose sum is σ = 1331798572. Its totient is φ = 1295803872.

The previous prime is 1313801213. The next prime is 1313801267. The reversal of 1313801221 is 1221083131.

It is a happy number.

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 856440225 + 457360996 = 29265^2 + 21386^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313801221 - 2³ = 1313801213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1313801192 and 1313801201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313801201) 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, 8998566 + ... + 8998711.

It is an arithmetic number, because the mean of its divisors is an integer number (332949643).

Almost surely, 2^1313801221 is an apocalyptic number.

It is an amenable number.

1313801221 is a deficient number, since it is larger than the sum of its proper divisors (17997351).

1313801221 is an equidigital number, since it uses as much as digits as its factorization.

1313801221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17997350.

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

The square root of 1313801221 is about 36246.3959725653. The cubic root of 1313801221 is about 1095.2414891028.

Adding to 1313801221 its reverse (1221083131), we get a palindrome (2534884352).

The spelling of 1313801221 in words is "one billion, three hundred thirteen million, eight hundred one thousand, two hundred twenty-one".