201820211 has 2 divisors, whose sum is σ = 201820212. Its totient is φ = 201820210.

The previous prime is 201820187. The next prime is 201820217. The reversal of 201820211 is 112028102.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201820211 - 2²² = 197625907 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 201820211.

It is not a weakly prime, because it can be changed into another prime (201820217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100910105 + 100910106.

It is an arithmetic number, because the mean of its divisors is an integer number (100910106).

Almost surely, 2^201820211 is an apocalyptic number.

201820211 is a deficient number, since it is larger than the sum of its proper divisors (1).

201820211 is an equidigital number, since it uses as much as digits as its factorization.

201820211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 201820211 is about 14206.3440406038. The cubic root of 201820211 is about 586.5723023515.

Adding to 201820211 its reverse (112028102), we get a palindrome (313848313).

It can be divided in two parts, 2018202 and 11, that multiplied together give a palindrome (22200222).

The spelling of 201820211 in words is "two hundred one million, eight hundred twenty thousand, two hundred eleven".