217168 has 30 divisors (see below), whose sum is σ = 491226. Its totient is φ = 92736.

The previous prime is 217163. The next prime is 217169. The reversal of 217168 is 861712.

It can be written as a sum of positive squares in only one way, i.e., 153664 + 63504 = 392^2 + 252^2 .

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217163) by changing a digit.

217168 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 646 + ... + 922.

2²¹⁷¹⁶⁸ is an apocalyptic number.

217168 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245613).

217168 is an abundant number, since it is smaller than the sum of its proper divisors (274058).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217168 is a wasteful number, since it uses less digits than its factorization.

217168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299 (or 286 counting only the distinct ones).

The product of its digits is 672, while the sum is 25.

The square root of 217168 is about 466.0128753586. The cubic root of 217168 is about 60.1079537979.

The spelling of 217168 in words is "two hundred seventeen thousand, one hundred sixty-eight".