681595361 has 2 divisors, whose sum is σ = 681595362. Its totient is φ = 681595360.

The previous prime is 681595337. The next prime is 681595403. The reversal of 681595361 is 163595186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 538936225 + 142659136 = 23215^2 + 11944^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681595361 is a prime.

It is a super-2 number, since 2×681595361² = 929144472273440642, which 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 (681595861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340797680 + 340797681.

It is an arithmetic number, because the mean of its divisors is an integer number (340797681).

Almost surely, 2^681595361 is an apocalyptic number.

It is an amenable number.

681595361 is a deficient number, since it is larger than the sum of its proper divisors (1).

681595361 is an equidigital number, since it uses as much as digits as its factorization.

681595361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 44.

The square root of 681595361 is about 26107.3813508747. The cubic root of 681595361 is about 880.0530964003.

The spelling of 681595361 in words is "six hundred eighty-one million, five hundred ninety-five thousand, three hundred sixty-one".