21002001220217 has 2 divisors, whose sum is σ = 21002001220218. Its totient is φ = 21002001220216.

The previous prime is 21002001220121. The next prime is 21002001220267. The reversal of 21002001220217 is 71202210020012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12198562110736 + 8803439109481 = 3492644^2 + 2967059^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002001220217 - 2¹⁶ = 21002001154681 is a prime.

It is not a weakly prime, because it can be changed into another prime (21002001220267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501000610108 + 10501000610109.

It is an arithmetic number, because the mean of its divisors is an integer number (10501000610109).

Almost surely, 2^{21002001220217} is an apocalyptic number.

It is an amenable number.

21002001220217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002001220217 is an equidigital number, since it uses as much as digits as its factorization.

21002001220217 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 21002001220217 its reverse (71202210020012), we get a palindrome (92204211240229).

The spelling of 21002001220217 in words is "twenty-one trillion, two billion, one million, two hundred twenty thousand, two hundred seventeen".