194809 has 2 divisors, whose sum is σ = 194810. Its totient is φ = 194808.

The previous prime is 194771. The next prime is 194813. The reversal of 194809 is 908491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162409 + 32400 = 403^2 + 180^2 .

It is an emirp because it is prime and its reverse (908491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194809 - 2⁷ = 194681 is a prime.

It is a Chen prime.

It is a plaindrome in base 11.

It is not a weakly prime, because it can be changed into another prime (194819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97404 + 97405.

It is an arithmetic number, because the mean of its divisors is an integer number (97405).

2¹⁹⁴⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

194809 is a deficient number, since it is larger than the sum of its proper divisors (1).

194809 is an equidigital number, since it uses as much as digits as its factorization.

194809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 194809 is about 441.3717254197. The cubic root of 194809 is about 57.9699606635.

The spelling of 194809 in words is "one hundred ninety-four thousand, eight hundred nine".