21000220031017 has 2 divisors, whose sum is σ = 21000220031018. Its totient is φ = 21000220031016.

The previous prime is 21000220030981. The next prime is 21000220031041. The reversal of 21000220031017 is 71013002200012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17342318976921 + 3657901054096 = 4164411^2 + 1912564^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000220031017 - 2²³ = 21000211642409 is a prime.

It is a super-3 number, since 3×21000220031017³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 21000220030985 and 21000220031003.

It is not a weakly prime, because it can be changed into another prime (21000220031117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500110015508 + 10500110015509.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110015509).

Almost surely, 2^{21000220031017} is an apocalyptic number.

It is an amenable number.

21000220031017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000220031017 is an equidigital number, since it uses as much as digits as its factorization.

21000220031017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 19.

Adding to 21000220031017 its reverse (71013002200012), we get a palindrome (92013222231029).

The spelling of 21000220031017 in words is "twenty-one trillion, two hundred twenty million, thirty-one thousand, seventeen".