21011221120117 has 2 divisors, whose sum is σ = 21011221120118. Its totient is φ = 21011221120116.

The previous prime is 21011221120093. The next prime is 21011221120121. The reversal of 21011221120117 is 71102112211012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20970226614276 + 40994505841 = 4579326^2 + 202471^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011221120117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011221120187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505610560058 + 10505610560059.

It is an arithmetic number, because the mean of its divisors is an integer number (10505610560059).

Almost surely, 2^{21011221120117} is an apocalyptic number.

It is an amenable number.

21011221120117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011221120117 is an equidigital number, since it uses as much as digits as its factorization.

21011221120117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 22.

Adding to 21011221120117 its reverse (71102112211012), we get a palindrome (92113333331129).

The spelling of 21011221120117 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, one hundred twenty thousand, one hundred seventeen".