217028 has 24 divisors (see below), whose sum is σ = 454272. Its totient is φ = 88704.

The previous prime is 217027. The next prime is 217033. The reversal of 217028 is 820712.

It is an Ulam number.

It is a plaindrome in base 15.

It is a zygodrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 217028.

It is not an unprimeable number, because it can be changed into a prime (217027) 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, 476 + ... + 812.

It is an arithmetic number, because the mean of its divisors is an integer number (18928).

2²¹⁷⁰²⁸ is an apocalyptic number.

217028 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 217028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227136).

217028 is an abundant number, since it is smaller than the sum of its proper divisors (237244).

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

217028 is a wasteful number, since it uses less digits than its factorization.

217028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371 (or 369 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 217028 is about 465.8626407000. The cubic root of 217028 is about 60.0950345795.

The spelling of 217028 in words is "two hundred seventeen thousand, twenty-eight".