216890 has 24 divisors (see below), whose sum is σ = 418068. Its totient is φ = 80960.

The previous prime is 216877. The next prime is 216899. The reversal of 216890 is 98612.

216890 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 190969 + 25921 = 437^2 + 161^2 .

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5270 + ... + 5310.

2²¹⁶⁸⁹⁰ is an apocalyptic number.

216890 is a deficient number, since it is larger than the sum of its proper divisors (201178).

216890 is a wasteful number, since it uses less digits than its factorization.

216890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 216890 is about 465.7145048203. The cubic root of 216890 is about 60.0822944828.

The spelling of 216890 in words is "two hundred sixteen thousand, eight hundred ninety".