21120221117 has 2 divisors, whose sum is σ = 21120221118. Its totient is φ = 21120221116.

The previous prime is 21120221071. The next prime is 21120221141. The reversal of 21120221117 is 71112202112.

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., 18590231716 + 2529989401 = 136346^2 + 50299^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120221117 - 2⁶ = 21120221053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120221147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560110558 + 10560110559.

It is an arithmetic number, because the mean of its divisors is an integer number (10560110559).

Almost surely, 2^21120221117 is an apocalyptic number.

It is an amenable number.

21120221117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120221117 is an equidigital number, since it uses as much as digits as its factorization.

21120221117 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 20.

Adding to 21120221117 its reverse (71112202112), we get a palindrome (92232423229).

The spelling of 21120221117 in words is "twenty-one billion, one hundred twenty million, two hundred twenty-one thousand, one hundred seventeen".