216178 has 4 divisors (see below), whose sum is σ = 324270. Its totient is φ = 108088.

The previous prime is 216173. The next prime is 216179. The reversal of 216178 is 871612.

216178 is digitally balanced in base 2, 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., 178929 + 37249 = 423^2 + 193^2 .

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (216173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54043 + ... + 54046.

2²¹⁶¹⁷⁸ is an apocalyptic number.

216178 is a deficient number, since it is larger than the sum of its proper divisors (108092).

216178 is a wasteful number, since it uses less digits than its factorization.

216178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108091.

The product of its digits is 672, while the sum is 25.

The square root of 216178 is about 464.9494596190. The cubic root of 216178 is about 60.0164769562.

Subtracting from 216178 its sum of digits (25), we obtain a triangular number (216153 = T₆₅₇).

The spelling of 216178 in words is "two hundred sixteen thousand, one hundred seventy-eight".