1991884 has 12 divisors (see below), whose sum is σ = 3669400. Its totient is φ = 943488.

The previous prime is 1991881. The next prime is 1991893. The reversal of 1991884 is 4881991.

It is not an unprimeable number, because it can be changed into a prime (1991881) 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, 13029 + ... + 13180.

2^1991884 is an apocalyptic number.

It is an amenable number.

1991884 is a deficient number, since it is larger than the sum of its proper divisors (1677516).

1991884 is a wasteful number, since it uses less digits than its factorization.

1991884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26232 (or 26230 counting only the distinct ones).

The product of its digits is 20736, while the sum is 40.

The square root of 1991884 is about 1411.3412060873. The cubic root of 1991884 is about 125.8214486190.

It can be divided in two parts, 19918 and 84, that added together give a palindrome (20002).

The spelling of 1991884 in words is "one million, nine hundred ninety-one thousand, eight hundred eighty-four".