211217916817 has 2 divisors, whose sum is σ = 211217916818. Its totient is φ = 211217916816.

The previous prime is 211217916757. The next prime is 211217916851. The reversal of 211217916817 is 718619712112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211217453056 + 463761 = 459584^2 + 681^2 .

It is a cyclic number.

It is not a de Polignac number, because 211217916817 - 2¹¹ = 211217914769 is a prime.

It is a super-2 number, since 2×211217916817² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211217976817) 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, 105608958408 + 105608958409.

It is an arithmetic number, because the mean of its divisors is an integer number (105608958409).

Almost surely, 2^211217916817 is an apocalyptic number.

It is an amenable number.

211217916817 is a deficient number, since it is larger than the sum of its proper divisors (1).

211217916817 is an equidigital number, since it uses as much as digits as its factorization.

211217916817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 46.

The spelling of 211217916817 in words is "two hundred eleven billion, two hundred seventeen million, nine hundred sixteen thousand, eight hundred seventeen".