1983181 has 4 divisors (see below), whose sum is σ = 1986012. Its totient is φ = 1980352.

The previous prime is 1983143. The next prime is 1983197. The reversal of 1983181 is 1813891.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1813891 = 67 ⋅27073.

It can be written as a sum of positive squares in 2 ways, for example, as 697225 + 1285956 = 835^2 + 1134^2 .

It is a cyclic number.

It is not a de Polignac number, because 1983181 - 2⁷ = 1983053 is a prime.

It is a super-2 number, since 2×1983181² = 7866013757522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1983181 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1983881) 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, 501 + ... + 2053.

It is an arithmetic number, because the mean of its divisors is an integer number (496503).

2^1983181 is an apocalyptic number.

It is an amenable number.

1983181 is a deficient number, since it is larger than the sum of its proper divisors (2831).

1983181 is a wasteful number, since it uses less digits than its factorization.

1983181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2830.

The product of its digits is 1728, while the sum is 31.

The square root of 1983181 is about 1408.2545934596. The cubic root of 1983181 is about 125.6379334555.

The spelling of 1983181 in words is "one million, nine hundred eighty-three thousand, one hundred eighty-one".