217648 has 20 divisors (see below), whose sum is σ = 430528. Its totient is φ = 106560.

The previous prime is 217643. The next prime is 217661. The reversal of 217648 is 846712.

It is not an unprimeable number, because it can be changed into a prime (217643) 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, 865 + ... + 1087.

2²¹⁷⁶⁴⁸ is an apocalyptic number.

It is an amenable number.

217648 is a deficient number, since it is larger than the sum of its proper divisors (212880).

217648 is a wasteful number, since it uses less digits than its factorization.

217648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 286 counting only the distinct ones).

The product of its digits is 2688, while the sum is 28.

The square root of 217648 is about 466.5275983262. The cubic root of 217648 is about 60.1522061542.

The spelling of 217648 in words is "two hundred seventeen thousand, six hundred forty-eight".