215122217 has 2 divisors, whose sum is σ = 215122218. Its totient is φ = 215122216.

The previous prime is 215122207. The next prime is 215122247. The reversal of 215122217 is 712221512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155276521 + 59845696 = 12461^2 + 7736^2 .

It is a cyclic number.

It is not a de Polignac number, because 215122217 - 2⁶ = 215122153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 215122192 and 215122201.

It is not a weakly prime, because it can be changed into another prime (215122207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107561108 + 107561109.

It is an arithmetic number, because the mean of its divisors is an integer number (107561109).

Almost surely, 2^215122217 is an apocalyptic number.

It is an amenable number.

215122217 is a deficient number, since it is larger than the sum of its proper divisors (1).

215122217 is an equidigital number, since it uses as much as digits as its factorization.

215122217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 560, while the sum is 23.

The square root of 215122217 is about 14667.0452716285. The cubic root of 215122217 is about 599.1861345004.

Adding to 215122217 its reverse (712221512), we get a palindrome (927343729).

The spelling of 215122217 in words is "two hundred fifteen million, one hundred twenty-two thousand, two hundred seventeen".