21120220117 has 2 divisors, whose sum is σ = 21120220118. Its totient is φ = 21120220116.

The previous prime is 21120220109. The next prime is 21120220129. The reversal of 21120220117 is 71102202112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13821764356 + 7298455761 = 117566^2 + 85431^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120220117 - 2³ = 21120220109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120220094 and 21120220103.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120221117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560110058 + 10560110059.

It is an arithmetic number, because the mean of its divisors is an integer number (10560110059).

Almost surely, 2^21120220117 is an apocalyptic number.

It is an amenable number.

21120220117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120220117 is an equidigital number, since it uses as much as digits as its factorization.

21120220117 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 19.

Adding to 21120220117 its reverse (71102202112), we get a palindrome (92222422229).

The spelling of 21120220117 in words is "twenty-one billion, one hundred twenty million, two hundred twenty thousand, one hundred seventeen".