21230442017 has 2 divisors, whose sum is σ = 21230442018. Its totient is φ = 21230442016.

The previous prime is 21230442011. The next prime is 21230442049. The reversal of 21230442017 is 71024403212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11319044881 + 9911397136 = 106391^2 + 99556^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230442017 - 2⁸ = 21230441761 is a prime.

It is not a weakly prime, because it can be changed into another prime (21230442011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615221008 + 10615221009.

It is an arithmetic number, because the mean of its divisors is an integer number (10615221009).

Almost surely, 2^21230442017 is an apocalyptic number.

It is an amenable number.

21230442017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230442017 is an equidigital number, since it uses as much as digits as its factorization.

21230442017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 26.

Adding to 21230442017 its reverse (71024403212), we get a palindrome (92254845229).

The spelling of 21230442017 in words is "twenty-one billion, two hundred thirty million, four hundred forty-two thousand, seventeen".