1313213021 has 2 divisors, whose sum is σ = 1313213022. Its totient is φ = 1313213020.

The previous prime is 1313212993. The next prime is 1313213029. The reversal of 1313213021 is 1203123131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 810825625 + 502387396 = 28475^2 + 22414^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313213021 - 2¹⁰ = 1313211997 is a prime.

It is a super-3 number, since 3×1313213021³ (a number of 28 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1313213029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656606510 + 656606511.

It is an arithmetic number, because the mean of its divisors is an integer number (656606511).

Almost surely, 2^1313213021 is an apocalyptic number.

It is an amenable number.

1313213021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1313213021 is an equidigital number, since it uses as much as digits as its factorization.

1313213021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1313213021 is about 36238.2811540503. The cubic root of 1313213021 is about 1095.0780150555.

Adding to 1313213021 its reverse (1203123131), we get a palindrome (2516336152).

The spelling of 1313213021 in words is "one billion, three hundred thirteen million, two hundred thirteen thousand, twenty-one".