681305120663 has 2 divisors, whose sum is σ = 681305120664. Its totient is φ = 681305120662.

The previous prime is 681305120659. The next prime is 681305120737. The reversal of 681305120663 is 366021503186.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 681305120663 - 2² = 681305120659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 681305120663.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681305120653) 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, 340652560331 + 340652560332.

It is an arithmetic number, because the mean of its divisors is an integer number (340652560332).

Almost surely, 2^681305120663 is an apocalyptic number.

681305120663 is a deficient number, since it is larger than the sum of its proper divisors (1).

681305120663 is an equidigital number, since it uses as much as digits as its factorization.

681305120663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 41.

The spelling of 681305120663 in words is "six hundred eighty-one billion, three hundred five million, one hundred twenty thousand, six hundred sixty-three".