206742139 has 4 divisors (see below), whose sum is σ = 207056520. Its totient is φ = 206427760.

The previous prime is 206742121. The next prime is 206742149. The reversal of 206742139 is 931247602.

206742139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206742139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206742149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156202 + ... + 157519.

It is an arithmetic number, because the mean of its divisors is an integer number (51764130).

Almost surely, 2^206742139 is an apocalyptic number.

206742139 is a deficient number, since it is larger than the sum of its proper divisors (314381).

206742139 is an equidigital number, since it uses as much as digits as its factorization.

206742139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314380.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 206742139 is about 14378.5304881966. The cubic root of 206742139 is about 591.3024363383.

The spelling of 206742139 in words is "two hundred six million, seven hundred forty-two thousand, one hundred thirty-nine".