199681589 has 2 divisors, whose sum is σ = 199681590. Its totient is φ = 199681588.

The previous prime is 199681567. The next prime is 199681619. The reversal of 199681589 is 985186991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186540964 + 13140625 = 13658^2 + 3625^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199681589 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199681529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99840794 + 99840795.

It is an arithmetic number, because the mean of its divisors is an integer number (99840795).

Almost surely, 2^199681589 is an apocalyptic number.

It is an amenable number.

199681589 is a deficient number, since it is larger than the sum of its proper divisors (1).

199681589 is an equidigital number, since it uses as much as digits as its factorization.

199681589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 56.

The square root of 199681589 is about 14130.8736106442. The cubic root of 199681589 is about 584.4930363299.

The spelling of 199681589 in words is "one hundred ninety-nine million, six hundred eighty-one thousand, five hundred eighty-nine".