21110211217 has 2 divisors, whose sum is σ = 21110211218. Its totient is φ = 21110211216.

The previous prime is 21110211211. The next prime is 21110211229. The reversal of 21110211217 is 71211201112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20969646481 + 140564736 = 144809^2 + 11856^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110211217 - 2³ = 21110211209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110211194 and 21110211203.

It is not a weakly prime, because it can be changed into another prime (21110211211) 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, 10555105608 + 10555105609.

It is an arithmetic number, because the mean of its divisors is an integer number (10555105609).

Almost surely, 2^21110211217 is an apocalyptic number.

It is an amenable number.

21110211217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110211217 is an equidigital number, since it uses as much as digits as its factorization.

21110211217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 19.

Adding to 21110211217 its reverse (71211201112), we get a palindrome (92321412329).

The spelling of 21110211217 in words is "twenty-one billion, one hundred ten million, two hundred eleven thousand, two hundred seventeen".