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BaseRepresentation
bin11100011010
32111100
4130122
524233
612230
75205
oct3432
92440
101818
111403
121076
13a9b
1493c
15813
hex71a

1818 has 12 divisors (see below), whose sum is σ = 3978. Its totient is φ = 600.

The previous prime is 1811. The next prime is 1823. The reversal of 1818 is 8181.

1818 divided by its sum of digits (18) gives a palindrome (101).

Adding to 1818 its reverse (8181), we get a palindrome (9999).

It can be divided in two parts, 18 and 18, that added together give a triangular number (36 = T8).

It is a happy number.

1818 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in only one way, i.e., 1089 + 729 = 33^2 + 27^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 101 = 1818 / (1 + 8 + 1 + 8).

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

1818 is an undulating number in base 10.

It is a Curzon number.

It is a nialpdrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 1818.

It is not an unprimeable number, because it can be changed into a prime (1811) 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, 33 + ... + 68.

1818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1818 is an abundant number, since it is smaller than the sum of its proper divisors (2160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1818 is a wasteful number, since it uses less digits than its factorization.

1818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 106 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

The square root of 1818 is about 42.6380112107. The cubic root of 1818 is about 12.2048175903.

The spelling of 1818 in words is "one thousand, eight hundred eighteen".

Divisors: 1 2 3 6 9 18 101 202 303 606 909 1818