217116172 has 48 divisors (see below), whose sum is σ = 472256512. Its totient is φ = 85043520.

The previous prime is 217116169. The next prime is 217116191. The reversal of 217116172 is 271611712.

217116172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 217116172.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34597 + ... + 40387.

Almost surely, 2^217116172 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217116172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (236128256).

217116172 is an abundant number, since it is smaller than the sum of its proper divisors (255140340).

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

217116172 is a wasteful number, since it uses less digits than its factorization.

217116172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5918 (or 5916 counting only the distinct ones).

The product of its digits is 1176, while the sum is 28.

The square root of 217116172 is about 14734.8624696670. The cubic root of 217116172 is about 601.0317175074.

Adding to 217116172 its reverse (271611712), we get a palindrome (488727884).

The spelling of 217116172 in words is "two hundred seventeen million, one hundred sixteen thousand, one hundred seventy-two".