21120011121217 has 2 divisors, whose sum is σ = 21120011121218. Its totient is φ = 21120011121216.

The previous prime is 21120011121173. The next prime is 21120011121221. The reversal of 21120011121217 is 71212111002112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21099406241281 + 20604879936 = 4593409^2 + 143544^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21120011121217 is a prime.

It is a super-2 number, since 2×21120011121217² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21120011121257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560005560608 + 10560005560609.

It is an arithmetic number, because the mean of its divisors is an integer number (10560005560609).

Almost surely, 2^{21120011121217} is an apocalyptic number.

It is an amenable number.

21120011121217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120011121217 is an equidigital number, since it uses as much as digits as its factorization.

21120011121217 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 21120011121217 its reverse (71212111002112), we get a palindrome (92332122123329).

The spelling of 21120011121217 in words is "twenty-one trillion, one hundred twenty billion, eleven million, one hundred twenty-one thousand, two hundred seventeen".