21021011022017 has 2 divisors, whose sum is σ = 21021011022018. Its totient is φ = 21021011022016.

The previous prime is 21021011021981. The next prime is 21021011022041. The reversal of 21021011022017 is 71022011012012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15756445974721 + 5264565047296 = 3969439^2 + 2294464^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021011022017 - 2⁶ = 21021011021953 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21021011022017.

It is not a weakly prime, because it can be changed into another prime (21021011022047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510505511008 + 10510505511009.

It is an arithmetic number, because the mean of its divisors is an integer number (10510505511009).

Almost surely, 2^{21021011022017} is an apocalyptic number.

It is an amenable number.

21021011022017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021011022017 is an equidigital number, since it uses as much as digits as its factorization.

21021011022017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 20.

Adding to 21021011022017 its reverse (71022011012012), we get a palindrome (92043022034029).

The spelling of 21021011022017 in words is "twenty-one trillion, twenty-one billion, eleven million, twenty-two thousand, seventeen".