206612975209 has 3 divisors (see below), whose sum is σ = 206613429757. Its totient is φ = 206612520662.

The previous prime is 206612975207. The next prime is 206612975213. The reversal of 206612975209 is 902579216602.

The square root of 206612975209 is 454547.

It is a perfect power (a square), and thus also a powerful number.

206612975209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 206612975209 - 2¹ = 206612975207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206612975207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 227274 + ... + 681820.

Almost surely, 2^206612975209 is an apocalyptic number.

206612975209 is the 454547-th square number.

206612975209 is the 227274-th centered octagonal number.

It is an amenable number.

206612975209 is a deficient number, since it is larger than the sum of its proper divisors (454548).

206612975209 is an frugal number, since it uses more digits than its factorization.

206612975209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909094 (or 454547 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 49.

Multiplying 206612975209 by its sum of digits (49), we get a square (10124035785241 = 3181829²).

The spelling of 206612975209 in words is "two hundred six billion, six hundred twelve million, nine hundred seventy-five thousand, two hundred nine".