206643139 has 2 divisors, whose sum is σ = 206643140. Its totient is φ = 206643138.

The previous prime is 206643133. The next prime is 206643167. The reversal of 206643139 is 931346602.

It is a happy number.

206643139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 206643139 - 2¹¹ = 206641091 is a prime.

It is not a weakly prime, because it can be changed into another prime (206643133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103321569 + 103321570.

It is an arithmetic number, because the mean of its divisors is an integer number (103321570).

Almost surely, 2^206643139 is an apocalyptic number.

206643139 is a deficient number, since it is larger than the sum of its proper divisors (1).

206643139 is an equidigital number, since it uses as much as digits as its factorization.

206643139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 34.

The square root of 206643139 is about 14375.0874432123. The cubic root of 206643139 is about 591.2080380895.

The spelling of 206643139 in words is "two hundred six million, six hundred forty-three thousand, one hundred thirty-nine".