209984441 has 2 divisors, whose sum is σ = 209984442. Its totient is φ = 209984440.

The previous prime is 209984429. The next prime is 209984443. The reversal of 209984441 is 144489902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136796416 + 73188025 = 11696^2 + 8555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209984441 is a prime.

It is a Sophie Germain prime.

Together with 209984443, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (209984443) 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, 104992220 + 104992221.

It is an arithmetic number, because the mean of its divisors is an integer number (104992221).

Almost surely, 2^209984441 is an apocalyptic number.

It is an amenable number.

209984441 is a deficient number, since it is larger than the sum of its proper divisors (1).

209984441 is an equidigital number, since it uses as much as digits as its factorization.

209984441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 209984441 is about 14490.8398997436. The cubic root of 209984441 is about 594.3775153135.

The spelling of 209984441 in words is "two hundred nine million, nine hundred eighty-four thousand, four hundred forty-one".