211221111217 has 2 divisors, whose sum is σ = 211221111218. Its totient is φ = 211221111216.

The previous prime is 211221111209. The next prime is 211221111253. The reversal of 211221111217 is 712111122112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115334272881 + 95886838336 = 339609^2 + 309656^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221111217 - 2³ = 211221111209 is a prime.

It is a super-2 number, since 2×211221111217² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211221111817) 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, 105610555608 + 105610555609.

It is an arithmetic number, because the mean of its divisors is an integer number (105610555609).

Almost surely, 2^211221111217 is an apocalyptic number.

It is an amenable number.

211221111217 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221111217 is an equidigital number, since it uses as much as digits as its factorization.

211221111217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 22.

Adding to 211221111217 its reverse (712111122112), we get a palindrome (923332233329).

The spelling of 211221111217 in words is "two hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, two hundred seventeen".