206006621 has 4 divisors (see below), whose sum is σ = 207896700. Its totient is φ = 204116544.

The previous prime is 206006611. The next prime is 206006627. The reversal of 206006621 is 126600602.

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 154008100 + 51998521 = 12410^2 + 7211^2 .

It is a cyclic number.

It is not a de Polignac number, because 206006621 - 2⁶ = 206006557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206006627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944876 + ... + 945093.

It is an arithmetic number, because the mean of its divisors is an integer number (51974175).

Almost surely, 2^206006621 is an apocalyptic number.

It is an amenable number.

206006621 is a deficient number, since it is larger than the sum of its proper divisors (1890079).

206006621 is a wasteful number, since it uses less digits than its factorization.

206006621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1890078.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 206006621 is about 14352.9307460184. The cubic root of 206006621 is about 590.6003856786.

The spelling of 206006621 in words is "two hundred six million, six thousand, six hundred twenty-one".