199669 has 2 divisors, whose sum is σ = 199670. Its totient is φ = 199668.

The previous prime is 199657. The next prime is 199673. The reversal of 199669 is 966991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180625 + 19044 = 425^2 + 138^2 .

It is an emirp because it is prime and its reverse (966991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199669 - 2⁵ = 199637 is a prime.

It is a super-2 number, since 2×199669² = 79735419122, which contains 22 as substring.

199669 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199679) 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, 99834 + 99835.

It is an arithmetic number, because the mean of its divisors is an integer number (99835).

2¹⁹⁹⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

199669 is a deficient number, since it is larger than the sum of its proper divisors (1).

199669 is an equidigital number, since it uses as much as digits as its factorization.

199669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26244, while the sum is 40.

The square root of 199669 is about 446.8433730067. The cubic root of 199669 is about 58.4480752878.

It can be divided in two parts, 199 and 669, that added together give a palindrome (868).

The spelling of 199669 in words is "one hundred ninety-nine thousand, six hundred sixty-nine".