12781730617 has 2 divisors, whose sum is σ = 12781730618. Its totient is φ = 12781730616.

The previous prime is 12781730609. The next prime is 12781730641. The reversal of 12781730617 is 71603718721.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12772616256 + 9114361 = 113016^2 + 3019^2 .

It is a cyclic number.

It is not a de Polignac number, because 12781730617 - 2³ = 12781730609 is a prime.

It is not a weakly prime, because it can be changed into another prime (12781731617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6390865308 + 6390865309.

It is an arithmetic number, because the mean of its divisors is an integer number (6390865309).

Almost surely, 2^12781730617 is an apocalyptic number.

It is an amenable number.

12781730617 is a deficient number, since it is larger than the sum of its proper divisors (1).

12781730617 is an equidigital number, since it uses as much as digits as its factorization.

12781730617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 98784, while the sum is 43.

The spelling of 12781730617 in words is "twelve billion, seven hundred eighty-one million, seven hundred thirty thousand, six hundred seventeen".