206543 has 2 divisors, whose sum is σ = 206544. Its totient is φ = 206542.

The previous prime is 206527. The next prime is 206551. The reversal of 206543 is 345602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 206543 - 2⁴ = 206527 is a prime.

It is a super-3 number, since 3×206543³ = 26433379862355021, which contains 333 as substring.

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 (206593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103271 + 103272.

It is an arithmetic number, because the mean of its divisors is an integer number (103272).

2²⁰⁶⁵⁴³ is an apocalyptic number.

206543 is a deficient number, since it is larger than the sum of its proper divisors (1).

206543 is an equidigital number, since it uses as much as digits as its factorization.

206543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 206543 is about 454.4700210135. The cubic root of 206543 is about 59.1112523107. Note that the first 3 decimals are identical.

The spelling of 206543 in words is "two hundred six thousand, five hundred forty-three".