217842 has 8 divisors (see below), whose sum is σ = 435696. Its totient is φ = 72612.

The previous prime is 217829. The next prime is 217849. The reversal of 217842 is 248712.

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

217842 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 217842.

It is not an unprimeable number, because it can be changed into a prime (217849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18148 + ... + 18159.

It is an arithmetic number, because the mean of its divisors is an integer number (54462).

2²¹⁷⁸⁴² is an apocalyptic number.

217842 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

217842 is a wasteful number, since it uses less digits than its factorization.

217842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36312.

The product of its digits is 896, while the sum is 24.

The square root of 217842 is about 466.7354711183. The cubic root of 217842 is about 60.1700730195.

The spelling of 217842 in words is "two hundred seventeen thousand, eight hundred forty-two".