21200117 has 2 divisors, whose sum is σ = 21200118. Its totient is φ = 21200116.

The previous prime is 21200093. The next prime is 21200129. The reversal of 21200117 is 71100212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12013156 + 9186961 = 3466^2 + 3031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21200117 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21200147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600058 + 10600059.

It is an arithmetic number, because the mean of its divisors is an integer number (10600059).

Almost surely, 2^21200117 is an apocalyptic number.

It is an amenable number.

21200117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200117 is an equidigital number, since it uses as much as digits as its factorization.

21200117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 21200117 is about 4604.3584786591. The cubic root of 21200117 is about 276.7660098720.

Adding to 21200117 its reverse (71100212), we get a palindrome (92300329).

The spelling of 21200117 in words is "twenty-one million, two hundred thousand, one hundred seventeen".