1801818 has 32 divisors (see below), whose sum is σ = 4077120. Its totient is φ = 589680.

The previous prime is 1801817. The next prime is 1801819. The reversal of 1801818 is 8181081.

It is an interprime number because it is at equal distance from previous prime (1801817) and next prime (1801819).

It is a Harshad number since it is a multiple of its sum of digits (27).

1801818 is a modest number, since divided by 1818 gives 180 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 1801791 and 1801800.

It is not an unprimeable number, because it can be changed into a prime (1801817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3021 + ... + 3567.

It is an arithmetic number, because the mean of its divisors is an integer number (127410).

2^1801818 is an apocalyptic number.

1801818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1801818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2038560).

1801818 is an abundant number, since it is smaller than the sum of its proper divisors (2275302).

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

1801818 is a wasteful number, since it uses less digits than its factorization.

1801818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619 (or 613 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

The square root of 1801818 is about 1342.3181441074. The cubic root of 1801818 is about 121.6849796250.

Adding to 1801818 its reverse (8181081), we get a palindrome (9982899).

The spelling of 1801818 in words is "one million, eight hundred one thousand, eight hundred eighteen".