21220221211117 has 2 divisors, whose sum is σ = 21220221211118. Its totient is φ = 21220221211116.

The previous prime is 21220221211097. The next prime is 21220221211223. The reversal of 21220221211117 is 71111212202212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11361085925641 + 9859135285476 = 3370621^2 + 3139926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220221211117 - 2²³ = 21220212822509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220221211091 and 21220221211100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220221211517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610110605558 + 10610110605559.

It is an arithmetic number, because the mean of its divisors is an integer number (10610110605559).

Almost surely, 2^{21220221211117} is an apocalyptic number.

It is an amenable number.

21220221211117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220221211117 is an equidigital number, since it uses as much as digits as its factorization.

21220221211117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 21220221211117 its reverse (71111212202212), we get a palindrome (92331433413329).

The spelling of 21220221211117 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty-one million, two hundred eleven thousand, one hundred seventeen".