1981991182 has 8 divisors (see below), whose sum is σ = 2982547152. Its totient is φ = 987808800.

The previous prime is 1981991161. The next prime is 1981991191. The reversal of 1981991182 is 2811991891.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1592619 + ... + 1593862.

It is an arithmetic number, because the mean of its divisors is an integer number (372818394).

Almost surely, 2^1981991182 is an apocalyptic number.

1981991182 is a deficient number, since it is larger than the sum of its proper divisors (1000555970).

1981991182 is a wasteful number, since it uses less digits than its factorization.

1981991182 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3186794.

The product of its digits is 93312, while the sum is 49.

The square root of 1981991182 is about 44519.5595440925. The cubic root of 1981991182 is about 1256.1280275561.

The spelling of 1981991182 in words is "one billion, nine hundred eighty-one million, nine hundred ninety-one thousand, one hundred eighty-two".