1321243013 has 2 divisors, whose sum is σ = 1321243014. Its totient is φ = 1321243012.

The previous prime is 1321242997. The next prime is 1321243087. The reversal of 1321243013 is 3103421231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 856323169 + 464919844 = 29263^2 + 21562^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321243013 - 2⁴ = 1321242997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321243093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660621506 + 660621507.

It is an arithmetic number, because the mean of its divisors is an integer number (660621507).

Almost surely, 2^1321243013 is an apocalyptic number.

It is an amenable number.

1321243013 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321243013 is an equidigital number, since it uses as much as digits as its factorization.

1321243013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 1321243013 is about 36348.9066272976. The cubic root of 1321243013 is about 1097.3055300293.

Adding to 1321243013 its reverse (3103421231), we get a palindrome (4424664244).

The spelling of 1321243013 in words is "one billion, three hundred twenty-one million, two hundred forty-three thousand, thirteen".