209194243 has 2 divisors, whose sum is σ = 209194244. Its totient is φ = 209194242.

The previous prime is 209194241. The next prime is 209194261. The reversal of 209194243 is 342491902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209194243 - 2¹ = 209194241 is a prime.

Together with 209194241, it forms a pair of twin primes.

It is equal to p_11559391 and since 209194243 and 11559391 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 209194199 and 209194208.

It is not a weakly prime, because it can be changed into another prime (209194241) 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, 104597121 + 104597122.

It is an arithmetic number, because the mean of its divisors is an integer number (104597122).

Almost surely, 2^209194243 is an apocalyptic number.

209194243 is a deficient number, since it is larger than the sum of its proper divisors (1).

209194243 is an equidigital number, since it uses as much as digits as its factorization.

209194243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 209194243 is about 14463.5487692336. The cubic root of 209194243 is about 593.6310055461.

The spelling of 209194243 in words is "two hundred nine million, one hundred ninety-four thousand, two hundred forty-three".