1317812521 has 2 divisors, whose sum is σ = 1317812522. Its totient is φ = 1317812520.

The previous prime is 1317812513. The next prime is 1317812539. The reversal of 1317812521 is 1252187131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 695060496 + 622752025 = 26364^2 + 24955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1317812521 - 2³ = 1317812513 is a prime.

It is not a weakly prime, because it can be changed into another prime (1317810521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 658906260 + 658906261.

It is an arithmetic number, because the mean of its divisors is an integer number (658906261).

Almost surely, 2^1317812521 is an apocalyptic number.

It is an amenable number.

1317812521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1317812521 is an equidigital number, since it uses as much as digits as its factorization.

1317812521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 31.

The square root of 1317812521 is about 36301.6875778524. The cubic root of 1317812521 is about 1096.3550209499.

Adding to 1317812521 its reverse (1252187131), we get a palindrome (2569999652).

The spelling of 1317812521 in words is "one billion, three hundred seventeen million, eight hundred twelve thousand, five hundred twenty-one".