216826 has 4 divisors (see below), whose sum is σ = 325242. Its totient is φ = 108412.

The previous prime is 216803. The next prime is 216829. The reversal of 216826 is 628612.

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., 207025 + 9801 = 455^2 + 99^2 .

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 216826.

It is not an unprimeable number, because it can be changed into a prime (216829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54205 + ... + 54208.

2²¹⁶⁸²⁶ is an apocalyptic number.

216826 is the 295-th centered pentagonal number.

216826 is a deficient number, since it is larger than the sum of its proper divisors (108416).

216826 is a wasteful number, since it uses less digits than its factorization.

216826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108415.

The product of its digits is 1152, while the sum is 25.

The square root of 216826 is about 465.6457881266. The cubic root of 216826 is about 60.0763841978.

The spelling of 216826 in words is "two hundred sixteen thousand, eight hundred twenty-six".