206216081 has 2 divisors, whose sum is σ = 206216082. Its totient is φ = 206216080.

The previous prime is 206216053. The next prime is 206216093. The reversal of 206216081 is 180612602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191130625 + 15085456 = 13825^2 + 3884^2 .

It is a cyclic number.

It is not a de Polignac number, because 206216081 - 2²² = 202021777 is a prime.

It is a super-2 number, since 2×206216081² = 85050144125997122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206216081.

It is not a weakly prime, because it can be changed into another prime (206216041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103108040 + 103108041.

It is an arithmetic number, because the mean of its divisors is an integer number (103108041).

Almost surely, 2^206216081 is an apocalyptic number.

It is an amenable number.

206216081 is a deficient number, since it is larger than the sum of its proper divisors (1).

206216081 is an equidigital number, since it uses as much as digits as its factorization.

206216081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 206216081 is about 14360.2256597868. The cubic root of 206216081 is about 590.8004848354.

Adding to 206216081 its reverse (180612602), we get a palindrome (386828683).

The spelling of 206216081 in words is "two hundred six million, two hundred sixteen thousand, eighty-one".