217241217 has 8 divisors (see below), whose sum is σ = 321838880. Its totient is φ = 144827460.

The previous prime is 217241209. The next prime is 217241221. The reversal of 217241217 is 712142712.

It is a happy number.

217241217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 217241217 - 2³ = 217241209 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 8045971 = 217241217 / (2 + 1 + 7 + 2 + 4 + 1 + 2 + 1 + 7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217241207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4022959 + ... + 4023012.

It is an arithmetic number, because the mean of its divisors is an integer number (40229860).

Almost surely, 2^217241217 is an apocalyptic number.

217241217 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

217241217 is a deficient number, since it is larger than the sum of its proper divisors (104597663).

217241217 is an equidigital number, since it uses as much as digits as its factorization.

217241217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8045980 (or 8045974 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 217241217 is about 14739.1050271039. The cubic root of 217241217 is about 601.1470806126.

Adding to 217241217 its reverse (712142712), we get a palindrome (929383929).

The spelling of 217241217 in words is "two hundred seventeen million, two hundred forty-one thousand, two hundred seventeen".