206868409 has 16 divisors (see below), whose sum is σ = 238728960. Its totient is φ = 177282000.

The previous prime is 206868379. The next prime is 206868413. The reversal of 206868409 is 904868602.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 206868409 - 2¹⁵ = 206835641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206868419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41754 + ... + 46444.

It is an arithmetic number, because the mean of its divisors is an integer number (14920560).

Almost surely, 2^206868409 is an apocalyptic number.

It is an amenable number.

206868409 is a deficient number, since it is larger than the sum of its proper divisors (31860551).

206868409 is a wasteful number, since it uses less digits than its factorization.

206868409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4932.

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 206868409 is about 14382.9207395438. The cubic root of 206868409 is about 591.4227932937.

The spelling of 206868409 in words is "two hundred six million, eight hundred sixty-eight thousand, four hundred nine".