216161 has 8 divisors (see below), whose sum is σ = 241824. Its totient is φ = 191520.

The previous prime is 216157. The next prime is 216173. The reversal of 216161 is 161612.

216161 = T₇₈ + T₇₉ + ... + T₁₂₀.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216161 - 2² = 216157 is a prime.

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216161.

It is not an unprimeable number, because it can be changed into a prime (216061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245 + ... + 701.

It is an arithmetic number, because the mean of its divisors is an integer number (30228).

2²¹⁶¹⁶¹ is an apocalyptic number.

It is an amenable number.

216161 is a deficient number, since it is larger than the sum of its proper divisors (25663).

216161 is a wasteful number, since it uses less digits than its factorization.

216161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511.

The product of its digits is 72, while the sum is 17.

The square root of 216161 is about 464.9311777027. The cubic root of 216161 is about 60.0149037051.

Adding to 216161 its reverse (161612), we get a palindrome (377773).

It can be divided in two parts, 2161 and 61, that added together give a palindrome (2222).

The spelling of 216161 in words is "two hundred sixteen thousand, one hundred sixty-one".