206665321 has 2 divisors, whose sum is σ = 206665322. Its totient is φ = 206665320.

The previous prime is 206665301. The next prime is 206665331. The reversal of 206665321 is 123566602.

206665321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160275600 + 46389721 = 12660^2 + 6811^2 .

It is a cyclic number.

It is not a de Polignac number, because 206665321 - 2¹¹ = 206663273 is a prime.

It is not a weakly prime, because it can be changed into another prime (206665301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103332660 + 103332661.

It is an arithmetic number, because the mean of its divisors is an integer number (103332661).

Almost surely, 2^206665321 is an apocalyptic number.

It is an amenable number.

206665321 is a deficient number, since it is larger than the sum of its proper divisors (1).

206665321 is an equidigital number, since it uses as much as digits as its factorization.

206665321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 206665321 is about 14375.8589656410. The cubic root of 206665321 is about 591.2291916388.

The spelling of 206665321 in words is "two hundred six million, six hundred sixty-five thousand, three hundred twenty-one".