1681818 has 8 divisors (see below), whose sum is σ = 3363648. Its totient is φ = 560604.

The previous prime is 1681817. The next prime is 1681837. The reversal of 1681818 is 8181861.

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

1681818 is an admirable number.

1681818 is a modest number, since divided by 1818 gives 168 as remainder.

It is not an unprimeable number, because it can be changed into a prime (1681817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140146 + ... + 140157.

It is an arithmetic number, because the mean of its divisors is an integer number (420456).

2^1681818 is an apocalyptic number.

1681818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1681818 is a wasteful number, since it uses less digits than its factorization.

1681818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280308.

The product of its digits is 3072, while the sum is 33.

The square root of 1681818 is about 1296.8492587807. The cubic root of 1681818 is about 118.9213047479.

It can be divided in two parts, 16818 and 18, that added together give a triangular number (16836 = T₁₈₃).

The spelling of 1681818 in words is "one million, six hundred eighty-one thousand, eight hundred eighteen".