206306669 has 2 divisors, whose sum is σ = 206306670. Its totient is φ = 206306668.

The previous prime is 206306651. The next prime is 206306671. The reversal of 206306669 is 966603602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177555625 + 28751044 = 13325^2 + 5362^2 .

It is a cyclic number.

It is not a de Polignac number, because 206306669 - 2¹² = 206302573 is a prime.

It is a super-2 number, since 2×206306669² = 85124883347751122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 206306671, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206306069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103153334 + 103153335.

It is an arithmetic number, because the mean of its divisors is an integer number (103153335).

Almost surely, 2^206306669 is an apocalyptic number.

It is an amenable number.

206306669 is a deficient number, since it is larger than the sum of its proper divisors (1).

206306669 is an equidigital number, since it uses as much as digits as its factorization.

206306669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 38.

The square root of 206306669 is about 14363.3794421786. The cubic root of 206306669 is about 590.8869824535.

The spelling of 206306669 in words is "two hundred six million, three hundred six thousand, six hundred sixty-nine".