21211112017 has 2 divisors, whose sum is σ = 21211112018. Its totient is φ = 21211112016.

The previous prime is 21211111979. The next prime is 21211112147. The reversal of 21211112017 is 71021111212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21192371776 + 18740241 = 145576^2 + 4329^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211112017 - 2¹⁵ = 21211079249 is a prime.

It is a super-2 number, since 2×21211112017² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21211111985 and 21211112003.

It is not a weakly prime, because it can be changed into another prime (21211110017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605556008 + 10605556009.

It is an arithmetic number, because the mean of its divisors is an integer number (10605556009).

Almost surely, 2^21211112017 is an apocalyptic number.

It is an amenable number.

21211112017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211112017 is an equidigital number, since it uses as much as digits as its factorization.

21211112017 is an evil number, because the sum of its binary digits is even.

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

Adding to 21211112017 its reverse (71021111212), we get a palindrome (92232223229).

The spelling of 21211112017 in words is "twenty-one billion, two hundred eleven million, one hundred twelve thousand, seventeen".