206440005 has 32 divisors (see below), whose sum is σ = 344171520. Its totient is φ = 105546240.

The previous prime is 206439977. The next prime is 206440021. The reversal of 206440005 is 500044602.

It is a happy number.

It is not a de Polignac number, because 206440005 - 2⁸ = 206439749 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 48649 + ... + 52721.

It is an arithmetic number, because the mean of its divisors is an integer number (10755360).

Almost surely, 2^206440005 is an apocalyptic number.

It is an amenable number.

206440005 is a deficient number, since it is larger than the sum of its proper divisors (137731515).

206440005 is a wasteful number, since it uses less digits than its factorization.

206440005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4221.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 206440005 is about 14368.0202185270. The cubic root of 206440005 is about 591.0142517914.

Adding to 206440005 its reverse (500044602), we get a palindrome (706484607).

The spelling of 206440005 in words is "two hundred six million, four hundred forty thousand, five".