21011031222217 has 2 divisors, whose sum is σ = 21011031222218. Its totient is φ = 21011031222216.

The previous prime is 21011031222193. The next prime is 21011031222229. The reversal of 21011031222217 is 71222213011012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20783970395136 + 227060827081 = 4558944^2 + 476509^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011031222217 - 2²³ = 21011022833609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011031222191 and 21011031222200.

It is not a weakly prime, because it can be changed into another prime (21011031222257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505515611108 + 10505515611109.

It is an arithmetic number, because the mean of its divisors is an integer number (10505515611109).

Almost surely, 2^{21011031222217} is an apocalyptic number.

It is an amenable number.

21011031222217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011031222217 is an equidigital number, since it uses as much as digits as its factorization.

21011031222217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 25.

Adding to 21011031222217 its reverse (71222213011012), we get a palindrome (92233244233229).

The spelling of 21011031222217 in words is "twenty-one trillion, eleven billion, thirty-one million, two hundred twenty-two thousand, two hundred seventeen".