681005593 has 2 divisors, whose sum is σ = 681005594. Its totient is φ = 681005592.

The previous prime is 681005569. The next prime is 681005599. The reversal of 681005593 is 395500186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671690889 + 9314704 = 25917^2 + 3052^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681005593 is a prime.

It is not a weakly prime, because it can be changed into another prime (681005599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340502796 + 340502797.

It is an arithmetic number, because the mean of its divisors is an integer number (340502797).

Almost surely, 2^681005593 is an apocalyptic number.

It is an amenable number.

681005593 is a deficient number, since it is larger than the sum of its proper divisors (1).

681005593 is an equidigital number, since it uses as much as digits as its factorization.

681005593 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 681005593 is about 26096.0838632926. The cubic root of 681005593 is about 879.7991935928.

The spelling of 681005593 in words is "six hundred eighty-one million, five thousand, five hundred ninety-three".