12781600649 has 2 divisors, whose sum is σ = 12781600650. Its totient is φ = 12781600648.

The previous prime is 12781600639. The next prime is 12781600673. The reversal of 12781600649 is 94600618721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12623646025 + 157954624 = 112355^2 + 12568^2 .

It is a cyclic number.

It is not a de Polignac number, because 12781600649 - 2⁸ = 12781600393 is a prime.

It is not a weakly prime, because it can be changed into another prime (12781600639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6390800324 + 6390800325.

It is an arithmetic number, because the mean of its divisors is an integer number (6390800325).

Almost surely, 2^12781600649 is an apocalyptic number.

It is an amenable number.

12781600649 is a deficient number, since it is larger than the sum of its proper divisors (1).

12781600649 is an equidigital number, since it uses as much as digits as its factorization.

12781600649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 12781600649 in words is "twelve billion, seven hundred eighty-one million, six hundred thousand, six hundred forty-nine".