21320310017 has 2 divisors, whose sum is σ = 21320310018. Its totient is φ = 21320310016.

The previous prime is 21320309981. The next prime is 21320310031. The reversal of 21320310017 is 71001302312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20671538176 + 648771841 = 143776^2 + 25471^2 .

It is a cyclic number.

It is not a de Polignac number, because 21320310017 - 2⁸ = 21320309761 is a prime.

It is not a weakly prime, because it can be changed into another prime (21320310217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660155008 + 10660155009.

It is an arithmetic number, because the mean of its divisors is an integer number (10660155009).

Almost surely, 2^21320310017 is an apocalyptic number.

It is an amenable number.

21320310017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21320310017 is an equidigital number, since it uses as much as digits as its factorization.

21320310017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 20.

Adding to 21320310017 its reverse (71001302312), we get a palindrome (92321612329).

The spelling of 21320310017 in words is "twenty-one billion, three hundred twenty million, three hundred ten thousand, seventeen".