1991704 has 32 divisors (see below), whose sum is σ = 4389840. Its totient is φ = 835200.

The previous prime is 1991681. The next prime is 1991707. The reversal of 1991704 is 4071991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991707) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274 + ... + 2014.

2^1991704 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1991704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2194920).

1991704 is an abundant number, since it is smaller than the sum of its proper divisors (2398136).

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

1991704 is a wasteful number, since it uses less digits than its factorization.

1991704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1771 (or 1767 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 1991704 is about 1411.2774355172. The cubic root of 1991704 is about 125.8176584815.

The spelling of 1991704 in words is "one million, nine hundred ninety-one thousand, seven hundred four".