681346807321 has 2 divisors, whose sum is σ = 681346807322. Its totient is φ = 681346807320.

The previous prime is 681346807283. The next prime is 681346807343. The reversal of 681346807321 is 123708643186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631173047296 + 50173760025 = 794464^2 + 223995^2 .

It is a cyclic number.

It is not a de Polignac number, because 681346807321 - 2⁹ = 681346806809 is a prime.

It is not a weakly prime, because it can be changed into another prime (681346801321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340673403660 + 340673403661.

It is an arithmetic number, because the mean of its divisors is an integer number (340673403661).

Almost surely, 2^681346807321 is an apocalyptic number.

It is an amenable number.

681346807321 is a deficient number, since it is larger than the sum of its proper divisors (1).

681346807321 is an equidigital number, since it uses as much as digits as its factorization.

681346807321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1161216, while the sum is 49.

The spelling of 681346807321 in words is "six hundred eighty-one billion, three hundred forty-six million, eight hundred seven thousand, three hundred twenty-one".