216330161 has 4 divisors (see below), whose sum is σ = 216616692. Its totient is φ = 216043632.

The previous prime is 216330137. The next prime is 216330173. The reversal of 216330161 is 161033612.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 50410000 + 165920161 = 7100^2 + 12881^2 .

It is a cyclic number.

It is not a de Polignac number, because 216330161 - 2¹⁰ = 216329137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216330131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142130 + ... + 143643.

It is an arithmetic number, because the mean of its divisors is an integer number (54154173).

Almost surely, 2^216330161 is an apocalyptic number.

It is an amenable number.

216330161 is a deficient number, since it is larger than the sum of its proper divisors (286531).

216330161 is an equidigital number, since it uses as much as digits as its factorization.

216330161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286530.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 216330161 is about 14708.1664730856. The cubic root of 216330161 is about 600.3055490029.

Adding to 216330161 its reverse (161033612), we get a palindrome (377363773).

The spelling of 216330161 in words is "two hundred sixteen million, three hundred thirty thousand, one hundred sixty-one".