206681663 has 2 divisors, whose sum is σ = 206681664. Its totient is φ = 206681662.

The previous prime is 206681647. The next prime is 206681687. The reversal of 206681663 is 366186602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 206681663 - 2⁴ = 206681647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206681063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103340831 + 103340832.

It is an arithmetic number, because the mean of its divisors is an integer number (103340832).

Almost surely, 2^206681663 is an apocalyptic number.

206681663 is a deficient number, since it is larger than the sum of its proper divisors (1).

206681663 is an equidigital number, since it uses as much as digits as its factorization.

206681663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 206681663 is about 14376.4273378333. The cubic root of 206681663 is about 591.2447749867.

The spelling of 206681663 in words is "two hundred six million, six hundred eighty-one thousand, six hundred sixty-three".