206877989 has 4 divisors (see below), whose sum is σ = 212469324. Its totient is φ = 201286656.

The previous prime is 206877971. The next prime is 206877991. The reversal of 206877989 is 989778602.

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

It can be written as a sum of positive squares in 2 ways, for example, as 107536900 + 99341089 = 10370^2 + 9967^2 .

It is a cyclic number.

It is not a de Polignac number, because 206877989 - 2⁸ = 206877733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206877949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2795612 + ... + 2795685.

It is an arithmetic number, because the mean of its divisors is an integer number (53117331).

Almost surely, 2^206877989 is an apocalyptic number.

It is an amenable number.

206877989 is a deficient number, since it is larger than the sum of its proper divisors (5591335).

206877989 is an equidigital number, since it uses as much as digits as its factorization.

206877989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5591334.

The product of its (nonzero) digits is 3048192, while the sum is 56.

The square root of 206877989 is about 14383.2537695752. The cubic root of 206877989 is about 591.4319226769.

The spelling of 206877989 in words is "two hundred six million, eight hundred seventy-seven thousand, nine hundred eighty-nine".