206820101 has 2 divisors, whose sum is σ = 206820102. Its totient is φ = 206820100.

The previous prime is 206820077. The next prime is 206820109. The reversal of 206820101 is 101028602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135163876 + 71656225 = 11626^2 + 8465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-206820101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206820109) 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, 103410050 + 103410051.

It is an arithmetic number, because the mean of its divisors is an integer number (103410051).

Almost surely, 2^206820101 is an apocalyptic number.

It is an amenable number.

206820101 is a deficient number, since it is larger than the sum of its proper divisors (1).

206820101 is an equidigital number, since it uses as much as digits as its factorization.

206820101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 206820101 is about 14381.2412885675. The cubic root of 206820101 is about 591.3767532746.

Adding to 206820101 its reverse (101028602), we get a palindrome (307848703).

The spelling of 206820101 in words is "two hundred six million, eight hundred twenty thousand, one hundred one".