21002112017 has 2 divisors, whose sum is σ = 21002112018. Its totient is φ = 21002112016.

The previous prime is 21002111993. The next prime is 21002112067. The reversal of 21002112017 is 71021120012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18322600321 + 2679511696 = 135361^2 + 51764^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002112017 - 2³² = 16707144721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002111986 and 21002112004.

It is not a weakly prime, because it can be changed into another prime (21002112067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501056008 + 10501056009.

It is an arithmetic number, because the mean of its divisors is an integer number (10501056009).

Almost surely, 2^21002112017 is an apocalyptic number.

It is an amenable number.

21002112017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002112017 is an equidigital number, since it uses as much as digits as its factorization.

21002112017 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 17.

Adding to 21002112017 its reverse (71021120012), we get a palindrome (92023232029).

The spelling of 21002112017 in words is "twenty-one billion, two million, one hundred twelve thousand, seventeen".