1981183 has 4 divisors (see below), whose sum is σ = 1993960. Its totient is φ = 1968408.

The previous prime is 1981181. The next prime is 1981201. The reversal of 1981183 is 3811891.

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

It is a cyclic number.

It is not a de Polignac number, because 1981183 - 2¹ = 1981181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6153 + ... + 6466.

It is an arithmetic number, because the mean of its divisors is an integer number (498490).

2^1981183 is an apocalyptic number.

1981183 is a deficient number, since it is larger than the sum of its proper divisors (12777).

1981183 is a wasteful number, since it uses less digits than its factorization.

1981183 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12776.

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

The square root of 1981183 is about 1407.5450259228. The cubic root of 1981183 is about 125.5957270309.

The spelling of 1981183 in words is "one million, nine hundred eighty-one thousand, one hundred eighty-three".