128217 has 8 divisors (see below), whose sum is σ = 173440. Its totient is φ = 84240.

The previous prime is 128213. The next prime is 128221. The reversal of 128217 is 712821.

It is an interprime number because it is at equal distance from previous prime (128213) and next prime (128221).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128217 - 2² = 128213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 128193 and 128202.

It is not an unprimeable number, because it can be changed into a prime (128213) 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 in 7 ways as a sum of consecutive naturals, for example, 34 + ... + 507.

It is an arithmetic number, because the mean of its divisors is an integer number (21680).

2¹²⁸²¹⁷ is an apocalyptic number.

It is an amenable number.

128217 is a deficient number, since it is larger than the sum of its proper divisors (45223).

128217 is an equidigital number, since it uses as much as digits as its factorization.

128217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623.

The product of its digits is 224, while the sum is 21.

The square root of 128217 is about 358.0740146953. The cubic root of 128217 is about 50.4253053825.

The spelling of 128217 in words is "one hundred twenty-eight thousand, two hundred seventeen".