217240 has 16 divisors (see below), whose sum is σ = 488880. Its totient is φ = 86880.

The previous prime is 217229. The next prime is 217241. The reversal of 217240 is 42712.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2676 + ... + 2755.

It is an arithmetic number, because the mean of its divisors is an integer number (30555).

2²¹⁷²⁴⁰ is an apocalyptic number.

217240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217240 is an abundant number, since it is smaller than the sum of its proper divisors (271640).

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

217240 is a wasteful number, since it uses less digits than its factorization.

217240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5442 (or 5438 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 217240 is about 466.0901200412. The cubic root of 217240 is about 60.1145958055.

Adding to 217240 its reverse (42712), we get a palindrome (259952).

The spelling of 217240 in words is "two hundred seventeen thousand, two hundred forty", and thus it is an iban number.