21102201217 has 2 divisors, whose sum is σ = 21102201218. Its totient is φ = 21102201216.

The previous prime is 21102201187. The next prime is 21102201233. The reversal of 21102201217 is 71210220112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20873314576 + 228886641 = 144476^2 + 15129^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102201217 - 2⁷ = 21102201089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21102201194 and 21102201203.

It is not a weakly prime, because it can be changed into another prime (21102201247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551100608 + 10551100609.

It is an arithmetic number, because the mean of its divisors is an integer number (10551100609).

Almost surely, 2^21102201217 is an apocalyptic number.

It is an amenable number.

21102201217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102201217 is an equidigital number, since it uses as much as digits as its factorization.

21102201217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 19.

Adding to 21102201217 its reverse (71210220112), we get a palindrome (92312421329).

The spelling of 21102201217 in words is "twenty-one billion, one hundred two million, two hundred one thousand, two hundred seventeen".