1981118 has 4 divisors (see below), whose sum is σ = 2971680. Its totient is φ = 990558.

The previous prime is 1981099. The next prime is 1981141. The reversal of 1981118 is 8111891.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495278 + ... + 495281.

It is an arithmetic number, because the mean of its divisors is an integer number (742920).

2^1981118 is an apocalyptic number.

1981118 is a deficient number, since it is larger than the sum of its proper divisors (990562).

1981118 is an equidigital number, since it uses as much as digits as its factorization.

1981118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990561.

The product of its digits is 576, while the sum is 29.

The square root of 1981118 is about 1407.5219358859. The cubic root of 1981118 is about 125.5943534725.

The spelling of 1981118 in words is "one million, nine hundred eighty-one thousand, one hundred eighteen".