217968870 has 64 divisors (see below), whose sum is σ = 599063040. Its totient is φ = 49721088.

The previous prime is 217968857. The next prime is 217968871. The reversal of 217968870 is 78869712.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217968871) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 169249 + ... + 170531.

It is an arithmetic number, because the mean of its divisors is an integer number (9360360).

Almost surely, 2^217968870 is an apocalyptic number.

217968870 is an abundant number, since it is smaller than the sum of its proper divisors (381094170).

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

217968870 is a wasteful number, since it uses less digits than its factorization.

217968870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2109.

The product of its (nonzero) digits is 338688, while the sum is 48.

The square root of 217968870 is about 14763.7688277757. The cubic root of 217968870 is about 601.8175166076.

The spelling of 217968870 in words is "two hundred seventeen million, nine hundred sixty-eight thousand, eight hundred seventy".