681998740559 has 2 divisors, whose sum is σ = 681998740560. Its totient is φ = 681998740558.

The previous prime is 681998740537. The next prime is 681998740567. The reversal of 681998740559 is 955047899186.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681998740559 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681998740492 and 681998740501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681998740529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340999370279 + 340999370280.

It is an arithmetic number, because the mean of its divisors is an integer number (340999370280).

Almost surely, 2^681998740559 is an apocalyptic number.

681998740559 is a deficient number, since it is larger than the sum of its proper divisors (1).

681998740559 is an equidigital number, since it uses as much as digits as its factorization.

681998740559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 195955200, while the sum is 71.

The spelling of 681998740559 in words is "six hundred eighty-one billion, nine hundred ninety-eight million, seven hundred forty thousand, five hundred fifty-nine".