215518117 has 2 divisors, whose sum is σ = 215518118. Its totient is φ = 215518116.

The previous prime is 215518109. The next prime is 215518123. The reversal of 215518117 is 711815512.

215518117 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189365121 + 26152996 = 13761^2 + 5114^2 .

It is a cyclic number.

It is not a de Polignac number, because 215518117 - 2³ = 215518109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215518817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107759058 + 107759059.

It is an arithmetic number, because the mean of its divisors is an integer number (107759059).

Almost surely, 2^215518117 is an apocalyptic number.

It is an amenable number.

215518117 is a deficient number, since it is larger than the sum of its proper divisors (1).

215518117 is an equidigital number, since it uses as much as digits as its factorization.

215518117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2800, while the sum is 31.

The square root of 215518117 is about 14680.5353104034. The cubic root of 215518117 is about 599.5534798190.

The spelling of 215518117 in words is "two hundred fifteen million, five hundred eighteen thousand, one hundred seventeen".