21711020017 has 2 divisors, whose sum is σ = 21711020018. Its totient is φ = 21711020016.

The previous prime is 21711019961. The next prime is 21711020083. The reversal of 21711020017 is 71002011712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17890667536 + 3820352481 = 133756^2 + 61809^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21711020017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21711020017.

It is not a weakly prime, because it can be changed into another prime (21711020087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855510008 + 10855510009.

It is an arithmetic number, because the mean of its divisors is an integer number (10855510009).

Almost surely, 2^21711020017 is an apocalyptic number.

It is an amenable number.

21711020017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21711020017 is an equidigital number, since it uses as much as digits as its factorization.

21711020017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 196, while the sum is 22.

Adding to 21711020017 its reverse (71002011712), we get a palindrome (92713031729).

The spelling of 21711020017 in words is "twenty-one billion, seven hundred eleven million, twenty thousand, seventeen".