1981018 has 12 divisors (see below), whose sum is σ = 3218238. Its totient is φ = 914160.

The previous prime is 1980991. The next prime is 1981037. The reversal of 1981018 is 8101891.

It can be written as a sum of positive squares in 3 ways, for example, as 946729 + 1034289 = 973^2 + 1017^2 .

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2593 + ... + 3268.

2^1981018 is an apocalyptic number.

1981018 is a deficient number, since it is larger than the sum of its proper divisors (1237220).

1981018 is a wasteful number, since it uses less digits than its factorization.

1981018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5889 (or 5876 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 1981018 is about 1407.4864120126. The cubic root of 1981018 is about 125.5922402471.

The spelling of 1981018 in words is "one million, nine hundred eighty-one thousand, eighteen".