21012222017 has 2 divisors, whose sum is σ = 21012222018. Its totient is φ = 21012222016.

The previous prime is 21012221981. The next prime is 21012222059. The reversal of 21012222017 is 71022221012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15231509056 + 5780712961 = 123416^2 + 76031^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012222017 - 2⁶ = 21012221953 is a prime.

It is a super-3 number, since 3×21012222017³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21012222017.

It is not a weakly prime, because it can be changed into another prime (21012222317) 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, 10506111008 + 10506111009.

It is an arithmetic number, because the mean of its divisors is an integer number (10506111009).

Almost surely, 2^21012222017 is an apocalyptic number.

It is an amenable number.

21012222017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012222017 is an equidigital number, since it uses as much as digits as its factorization.

21012222017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21012222017 its reverse (71022221012), we get a palindrome (92034443029).

The spelling of 21012222017 in words is "twenty-one billion, twelve million, two hundred twenty-two thousand, seventeen".