1991584 has 48 divisors (see below), whose sum is σ = 4753728. Its totient is φ = 801792.

The previous prime is 1991573. The next prime is 1991597. The reversal of 1991584 is 4851991.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3547 + ... + 4069.

It is an arithmetic number, because the mean of its divisors is an integer number (99036).

2^1991584 is an apocalyptic number.

1991584 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1991584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2376864).

1991584 is an abundant number, since it is smaller than the sum of its proper divisors (2762144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1991584 is a wasteful number, since it uses less digits than its factorization.

1991584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557 (or 549 counting only the distinct ones).

The product of its digits is 12960, while the sum is 37.

The square root of 1991584 is about 1411.2349202029. The cubic root of 1991584 is about 125.8151315963.

The spelling of 1991584 in words is "one million, nine hundred ninety-one thousand, five hundred eighty-four".