206868509 has 4 divisors (see below), whose sum is σ = 215862816. Its totient is φ = 197874204.

The previous prime is 206868469. The next prime is 206868533. The reversal of 206868509 is 905868602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 206868509 - 2⁸ = 206868253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 206868509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206868539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4497119 + ... + 4497164.

It is an arithmetic number, because the mean of its divisors is an integer number (53965704).

Almost surely, 2^206868509 is an apocalyptic number.

It is an amenable number.

206868509 is a deficient number, since it is larger than the sum of its proper divisors (8994307).

206868509 is an equidigital number, since it uses as much as digits as its factorization.

206868509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8994306.

The product of its (nonzero) digits is 207360, while the sum is 44.

The square root of 206868509 is about 14382.9242158888. The cubic root of 206868509 is about 591.4228885915.

The spelling of 206868509 in words is "two hundred six million, eight hundred sixty-eight thousand, five hundred nine".