217982 has 4 divisors (see below), whose sum is σ = 326976. Its totient is φ = 108990.

The previous prime is 217981. The next prime is 218003. The reversal of 217982 is 289712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54494 + ... + 54497.

It is an arithmetic number, because the mean of its divisors is an integer number (81744).

2²¹⁷⁹⁸² is an apocalyptic number.

217982 is a deficient number, since it is larger than the sum of its proper divisors (108994).

217982 is a wasteful number, since it uses less digits than its factorization.

217982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108993.

The product of its digits is 2016, while the sum is 29.

The square root of 217982 is about 466.8854249171. The cubic root of 217982 is about 60.1829600451.

The spelling of 217982 in words is "two hundred seventeen thousand, nine hundred eighty-two".