211806505208203 has 2 divisors, whose sum is σ = 211806505208204. Its totient is φ = 211806505208202.

The previous prime is 211806505208201. The next prime is 211806505208213. The reversal of 211806505208203 is 302802505608112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211806505208203 - 2¹ = 211806505208201 is a prime.

Together with 211806505208201, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 211806505208203.

It is not a weakly prime, because it can be changed into another prime (211806505208201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105903252604101 + 105903252604102.

It is an arithmetic number, because the mean of its divisors is an integer number (105903252604102).

Almost surely, 2^{211806505208203} is an apocalyptic number.

211806505208203 is a deficient number, since it is larger than the sum of its proper divisors (1).

211806505208203 is an equidigital number, since it uses as much as digits as its factorization.

211806505208203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 230400, while the sum is 43.

The spelling of 211806505208203 in words is "two hundred eleven trillion, eight hundred six billion, five hundred five million, two hundred eight thousand, two hundred three".