216173218 has 4 divisors (see below), whose sum is σ = 324259830. Its totient is φ = 108086608.

The previous prime is 216173213. The next prime is 216173219. The reversal of 216173218 is 812371612.

216173218 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 197880489 + 18292729 = 14067^2 + 4277^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 216173218.

It is not an unprimeable number, because it can be changed into a prime (216173213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54043303 + ... + 54043306.

Almost surely, 2^216173218 is an apocalyptic number.

216173218 is a deficient number, since it is larger than the sum of its proper divisors (108086612).

216173218 is a wasteful number, since it uses less digits than its factorization.

216173218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108086611.

The product of its digits is 4032, while the sum is 31.

The square root of 216173218 is about 14702.8302717538. The cubic root of 216173218 is about 600.1603441828.

The spelling of 216173218 in words is "two hundred sixteen million, one hundred seventy-three thousand, two hundred eighteen".