216361 has 6 divisors (see below), whose sum is σ = 226730. Its totient is φ = 206448.

The previous prime is 216347. The next prime is 216371. The reversal of 216361 is 163612.

216361 is digitally balanced in base 2, 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 only one way, i.e., 211600 + 4761 = 460^2 + 69^2 .

It is not a de Polignac number, because 216361 - 2⁵ = 216329 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (216371) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 325 + ... + 733.

2²¹⁶³⁶¹ is an apocalyptic number.

It is an amenable number.

216361 is a deficient number, since it is larger than the sum of its proper divisors (10369).

216361 is an equidigital number, since it uses as much as digits as its factorization.

216361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455 (or 432 counting only the distinct ones).

The product of its digits is 216, while the sum is 19.

The square root of 216361 is about 465.1462135716. The cubic root of 216361 is about 60.0334073217.

Adding to 216361 its reverse (163612), we get a palindrome (379973).

The spelling of 216361 in words is "two hundred sixteen thousand, three hundred sixty-one".