1313541221 has 2 divisors, whose sum is σ = 1313541222. Its totient is φ = 1313541220.

The previous prime is 1313541197. The next prime is 1313541277. The reversal of 1313541221 is 1221453131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1278849121 + 34692100 = 35761^2 + 5890^2 .

It is an emirp because it is prime and its reverse (1221453131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1313541221 - 2²² = 1309346917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1313549221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656770610 + 656770611.

It is an arithmetic number, because the mean of its divisors is an integer number (656770611).

Almost surely, 2^1313541221 is an apocalyptic number.

It is an amenable number.

1313541221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1313541221 is an equidigital number, since it uses as much as digits as its factorization.

1313541221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 1313541221 is about 36242.8092316255. The cubic root of 1313541221 is about 1095.1692352567.

Adding to 1313541221 its reverse (1221453131), we get a palindrome (2534994352).

The spelling of 1313541221 in words is "one billion, three hundred thirteen million, five hundred forty-one thousand, two hundred twenty-one".