1982181 has 4 divisors (see below), whose sum is σ = 2642912. Its totient is φ = 1321452.

The previous prime is 1982173. The next prime is 1982191. The reversal of 1982181 is 1812891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1982181 - 2³ = 1982173 is a prime.

It is a super-2 number, since 2×1982181² = 7858083033522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1982111) 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, 330361 + ... + 330366.

It is an arithmetic number, because the mean of its divisors is an integer number (660728).

2^1982181 is an apocalyptic number.

It is an amenable number.

1982181 is a deficient number, since it is larger than the sum of its proper divisors (660731).

1982181 is an equidigital number, since it uses as much as digits as its factorization.

1982181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660730.

The product of its digits is 1152, while the sum is 30.

The square root of 1982181 is about 1407.8994992541. The cubic root of 1982181 is about 125.6168126641.

The spelling of 1982181 in words is "one million, nine hundred eighty-two thousand, one hundred eighty-one".