206879989 has 2 divisors, whose sum is σ = 206879990. Its totient is φ = 206879988.

The previous prime is 206879977. The next prime is 206880007. The reversal of 206879989 is 989978602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111133764 + 95746225 = 10542^2 + 9785^2 .

It is a cyclic number.

It is not a de Polignac number, because 206879989 - 2⁷ = 206879861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206879489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103439994 + 103439995.

It is an arithmetic number, because the mean of its divisors is an integer number (103439995).

Almost surely, 2^206879989 is an apocalyptic number.

It is an amenable number.

206879989 is a deficient number, since it is larger than the sum of its proper divisors (1).

206879989 is an equidigital number, since it uses as much as digits as its factorization.

206879989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3919104, while the sum is 58.

The square root of 206879989 is about 14383.3232947049. The cubic root of 206879989 is about 591.4338285668.

The spelling of 206879989 in words is "two hundred six million, eight hundred seventy-nine thousand, nine hundred eighty-nine".