681308878193 has 2 divisors, whose sum is σ = 681308878194. Its totient is φ = 681308878192.

The previous prime is 681308878147. The next prime is 681308878199. The reversal of 681308878193 is 391878803186.

681308878193 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 551325555169 + 129983323024 = 742513^2 + 360532^2 .

It is a cyclic number.

It is not a de Polignac number, because 681308878193 - 2¹² = 681308874097 is a prime.

It is a super-2 number, since 2×681308878193² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (681308878199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340654439096 + 340654439097.

It is an arithmetic number, because the mean of its divisors is an integer number (340654439097).

Almost surely, 2^681308878193 is an apocalyptic number.

It is an amenable number.

681308878193 is a deficient number, since it is larger than the sum of its proper divisors (1).

681308878193 is an equidigital number, since it uses as much as digits as its factorization.

681308878193 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13934592, while the sum is 62.

The spelling of 681308878193 in words is "six hundred eighty-one billion, three hundred eight million, eight hundred seventy-eight thousand, one hundred ninety-three".