216172217 has 8 divisors (see below), whose sum is σ = 219660672. Its totient is φ = 212691600.

The previous prime is 216172211. The next prime is 216172247. The reversal of 216172217 is 712271612.

216172217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216172217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216172217.

It is not an unprimeable number, because it can be changed into a prime (216172211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81167 + ... + 83787.

It is an arithmetic number, because the mean of its divisors is an integer number (27457584).

Almost surely, 2^216172217 is an apocalyptic number.

It is an amenable number.

216172217 is a deficient number, since it is larger than the sum of its proper divisors (3488455).

216172217 is a wasteful number, since it uses less digits than its factorization.

216172217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3919.

The product of its digits is 2352, while the sum is 29.

The square root of 216172217 is about 14702.7962306495. The cubic root of 216172217 is about 600.1594178247.

The spelling of 216172217 in words is "two hundred sixteen million, one hundred seventy-two thousand, two hundred seventeen".