1861818 has 32 divisors (see below), whose sum is σ = 4308864. Its totient is φ = 525312.

The previous prime is 1861817. The next prime is 1861831. The reversal of 1861818 is 8181681.

1861818 is a modest number, since divided by 1818 gives 186 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1861817) 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 15 ways as a sum of consecutive naturals, for example, 3846 + ... + 4302.

It is an arithmetic number, because the mean of its divisors is an integer number (134652).

2^1861818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1861818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2154432).

1861818 is an abundant number, since it is smaller than the sum of its proper divisors (2447046).

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

1861818 is a wasteful number, since it uses less digits than its factorization.

1861818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566.

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

The square root of 1861818 is about 1364.4845180507. The cubic root of 1861818 is about 123.0209495680.

The spelling of 1861818 in words is "one million, eight hundred sixty-one thousand, eight hundred eighteen".