210021122221217 has 2 divisors, whose sum is σ = 210021122221218. Its totient is φ = 210021122221216.

The previous prime is 210021122221123. The next prime is 210021122221249. The reversal of 210021122221217 is 712122221120012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209907823334416 + 113298886801 = 14488196^2 + 336599^2 .

It is a cyclic number.

It is not a de Polignac number, because 210021122221217 - 2³⁸ = 209746244314273 is a prime.

It is a super-2 number, since 2×210021122221217² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (210021122221517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105010561110608 + 105010561110609.

It is an arithmetic number, because the mean of its divisors is an integer number (105010561110609).

Almost surely, 2^{210021122221217} is an apocalyptic number.

It is an amenable number.

210021122221217 is a deficient number, since it is larger than the sum of its proper divisors (1).

210021122221217 is an equidigital number, since it uses as much as digits as its factorization.

210021122221217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 26.

Adding to 210021122221217 its reverse (712122221120012), we get a palindrome (922143343341229).

The spelling of 210021122221217 in words is "two hundred ten trillion, twenty-one billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred seventeen".