206642399 has 2 divisors, whose sum is σ = 206642400. Its totient is φ = 206642398.

The previous prime is 206642383. The next prime is 206642437. The reversal of 206642399 is 993246602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 206642399 - 2⁴ = 206642383 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206642369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103321199 + 103321200.

It is an arithmetic number, because the mean of its divisors is an integer number (103321200).

Almost surely, 2^206642399 is an apocalyptic number.

206642399 is a deficient number, since it is larger than the sum of its proper divisors (1).

206642399 is an equidigital number, since it uses as much as digits as its factorization.

206642399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 206642399 is about 14375.0617042154. The cubic root of 206642399 is about 591.2073323729.

The spelling of 206642399 in words is "two hundred six million, six hundred forty-two thousand, three hundred ninety-nine".