1816 has 8 divisors (see below), whose sum is σ = 3420. Its totient is φ = 904.

The previous prime is 1811. The next prime is 1823. The reversal of 1816 is 6181.

It is a tau number, because it is divible by the number of its divisors (8).

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

It is a plaindrome in base 6.

It is a nialpdrome in base 13 and base 15.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 1816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1811) by changing a digit.

1816 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106 + ... + 121.

It is an amenable number.

1816 is a deficient number, since it is larger than the sum of its proper divisors (1604).

1816 is a wasteful number, since it uses less digits than its factorization.

1816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233 (or 229 counting only the distinct ones).

The product of its digits is 48, while the sum is 16.

The square root of 1816 is about 42.6145515053. The cubic root of 1816 is about 12.2003404008.

Adding to 1816 its reverse (6181), we get a palindrome (7997).

The spelling of 1816 in words is "one thousand, eight hundred sixteen".