206659989 has 6 divisors (see below), whose sum is σ = 298508886. Its totient is φ = 137773320.

The previous prime is 206659951. The next prime is 206660033. The reversal of 206659989 is 989956602.

It can be written as a sum of positive squares in only one way, i.e., 202123089 + 4536900 = 14217^2 + 2130^2 .

It is not a de Polignac number, because 206659989 - 2¹⁹ = 206135701 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206659909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11481102 + ... + 11481119.

It is an arithmetic number, because the mean of its divisors is an integer number (49751481).

Almost surely, 2^206659989 is an apocalyptic number.

It is an amenable number.

206659989 is a deficient number, since it is larger than the sum of its proper divisors (91848897).

206659989 is a wasteful number, since it uses less digits than its factorization.

206659989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22962227 (or 22962224 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The square root of 206659989 is about 14375.6735146566. The cubic root of 206659989 is about 591.2241069909.

The spelling of 206659989 in words is "two hundred six million, six hundred fifty-nine thousand, nine hundred eighty-nine".