206400605 has 4 divisors (see below), whose sum is σ = 247680732. Its totient is φ = 165120480.

The previous prime is 206400583. The next prime is 206400613. The reversal of 206400605 is 506004602.

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 128572921 + 77827684 = 11339^2 + 8822^2 .

It is a de Polignac number, because none of the positive numbers 2^k-206400605 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20640056 + ... + 20640065.

It is an arithmetic number, because the mean of its divisors is an integer number (61920183).

Almost surely, 2^206400605 is an apocalyptic number.

It is an amenable number.

206400605 is a deficient number, since it is larger than the sum of its proper divisors (41280127).

206400605 is an equidigital number, since it uses as much as digits as its factorization.

206400605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41280126.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 206400605 is about 14366.6490525801. The cubic root of 206400605 is about 590.9766501598.

The spelling of 206400605 in words is "two hundred six million, four hundred thousand, six hundred five".