199919689 has 2 divisors, whose sum is σ = 199919690. Its totient is φ = 199919688.

The previous prime is 199919659. The next prime is 199919701. The reversal of 199919689 is 986919991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123654400 + 76265289 = 11120^2 + 8733^2 .

It is a cyclic number.

It is not a de Polignac number, because 199919689 - 2¹³ = 199911497 is a prime.

It is not a weakly prime, because it can be changed into another prime (199919639) 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, 99959844 + 99959845.

It is an arithmetic number, because the mean of its divisors is an integer number (99959845).

Almost surely, 2^199919689 is an apocalyptic number.

It is an amenable number.

199919689 is a deficient number, since it is larger than the sum of its proper divisors (1).

199919689 is an equidigital number, since it uses as much as digits as its factorization.

199919689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2834352, while the sum is 61.

The square root of 199919689 is about 14139.2959159924. The cubic root of 199919689 is about 584.7252602332.

The spelling of 199919689 in words is "one hundred ninety-nine million, nine hundred nineteen thousand, six hundred eighty-nine".