1243120513 has 2 divisors, whose sum is σ = 1243120514. Its totient is φ = 1243120512.

The previous prime is 1243120447. The next prime is 1243120517. The reversal of 1243120513 is 3150213421.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1163696769 + 79423744 = 34113^2 + 8912^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243120513 - 2¹⁷ = 1242989441 is a prime.

It is not a weakly prime, because it can be changed into another prime (1243120517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621560256 + 621560257.

It is an arithmetic number, because the mean of its divisors is an integer number (621560257).

Almost surely, 2^1243120513 is an apocalyptic number.

It is an amenable number.

1243120513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243120513 is an equidigital number, since it uses as much as digits as its factorization.

1243120513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 1243120513 is about 35257.9141895830. The cubic root of 1243120513 is about 1075.2375211232.

Adding to 1243120513 its reverse (3150213421), we get a palindrome (4393333934).

The spelling of 1243120513 in words is "one billion, two hundred forty-three million, one hundred twenty thousand, five hundred thirteen".