681838782329917 has 2 divisors, whose sum is σ = 681838782329918. Its totient is φ = 681838782329916.

The previous prime is 681838782329863. The next prime is 681838782329953. The reversal of 681838782329917 is 719923287838186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 476403348675556 + 205435433654361 = 21826666^2 + 14333019^2 .

It is a cyclic number.

It is not a de Polignac number, because 681838782329917 - 2²⁷ = 681838648112189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681838782329717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340919391164958 + 340919391164959.

It is an arithmetic number, because the mean of its divisors is an integer number (340919391164959).

Almost surely, 2^{681838782329917} is an apocalyptic number.

It is an amenable number.

681838782329917 is a deficient number, since it is larger than the sum of its proper divisors (1).

681838782329917 is an equidigital number, since it uses as much as digits as its factorization.

681838782329917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3511517184, while the sum is 82.

The spelling of 681838782329917 in words is "six hundred eighty-one trillion, eight hundred thirty-eight billion, seven hundred eighty-two million, three hundred twenty-nine thousand, nine hundred seventeen".