21030003217 has 2 divisors, whose sum is σ = 21030003218. Its totient is φ = 21030003216.

The previous prime is 21030003209. The next prime is 21030003223. The reversal of 21030003217 is 71230003012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13627293696 + 7402709521 = 116736^2 + 86039^2 .

It is a cyclic number.

It is not a de Polignac number, because 21030003217 - 2³ = 21030003209 is a prime.

It is a super-2 number, since 2×21030003217² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21030003194 and 21030003203.

It is not a weakly prime, because it can be changed into another prime (21030003227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515001608 + 10515001609.

It is an arithmetic number, because the mean of its divisors is an integer number (10515001609).

Almost surely, 2^21030003217 is an apocalyptic number.

It is an amenable number.

21030003217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030003217 is an equidigital number, since it uses as much as digits as its factorization.

21030003217 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 19.

Adding to 21030003217 its reverse (71230003012), we get a palindrome (92260006229).

The spelling of 21030003217 in words is "twenty-one billion, thirty million, three thousand, two hundred seventeen".