20211021110017 has 2 divisors, whose sum is σ = 20211021110018. Its totient is φ = 20211021110016.

The previous prime is 20211021110011. The next prime is 20211021110051. The reversal of 20211021110017 is 71001112011202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19552235647681 + 658785462336 = 4421791^2 + 811656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20211021110017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211021109976 and 20211021110003.

It is not a weakly prime, because it can be changed into another prime (20211021110011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105510555008 + 10105510555009.

It is an arithmetic number, because the mean of its divisors is an integer number (10105510555009).

Almost surely, 2^{20211021110017} is an apocalyptic number.

It is an amenable number.

20211021110017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211021110017 is an equidigital number, since it uses as much as digits as its factorization.

20211021110017 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 19.

Adding to 20211021110017 its reverse (71001112011202), we get a palindrome (91212133121219).

The spelling of 20211021110017 in words is "twenty trillion, two hundred eleven billion, twenty-one million, one hundred ten thousand, seventeen".