181616 has 10 divisors (see below), whose sum is σ = 351912. Its totient is φ = 90800.

The previous prime is 181609. The next prime is 181619. The reversal of 181616 is 616181.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 181591 and 181600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5660 + ... + 5691.

2¹⁸¹⁶¹⁶ is an apocalyptic number.

181616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181616 is a deficient number, since it is larger than the sum of its proper divisors (170296).

181616 is a wasteful number, since it uses less digits than its factorization.

181616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11359 (or 11353 counting only the distinct ones).

The product of its digits is 288, while the sum is 23.

The square root of 181616 is about 426.1642875699. The cubic root of 181616 is about 56.6306268337.

Adding to 181616 its reverse (616181), we get a palindrome (797797).

It can be divided in two parts, 181 and 616, that added together give a palindrome (797).

The spelling of 181616 in words is "one hundred eighty-one thousand, six hundred sixteen".