206409389 has 2 divisors, whose sum is σ = 206409390. Its totient is φ = 206409388.

The previous prime is 206409373. The next prime is 206409391. The reversal of 206409389 is 983904602.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126450025 + 79959364 = 11245^2 + 8942^2 .

It is a cyclic number.

It is not a de Polignac number, because 206409389 - 2⁴ = 206409373 is a prime.

Together with 206409391, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206409319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103204694 + 103204695.

It is an arithmetic number, because the mean of its divisors is an integer number (103204695).

Almost surely, 2^206409389 is an apocalyptic number.

It is an amenable number.

206409389 is a deficient number, since it is larger than the sum of its proper divisors (1).

206409389 is an equidigital number, since it uses as much as digits as its factorization.

206409389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 206409389 is about 14366.9547573590. The cubic root of 206409389 is about 590.9850336385.

The spelling of 206409389 in words is "two hundred six million, four hundred nine thousand, three hundred eighty-nine".