1991744 has 14 divisors (see below), whose sum is σ = 3952494. Its totient is φ = 995840.

The previous prime is 1991729. The next prime is 1991753. The reversal of 1991744 is 4471991.

1991744 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 1721344 + 270400 = 1312^2 + 520^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15497 + ... + 15624.

It is an arithmetic number, because the mean of its divisors is an integer number (282321).

2^1991744 is an apocalyptic number.

It is an amenable number.

1991744 is a deficient number, since it is larger than the sum of its proper divisors (1960750).

1991744 is an equidigital number, since it uses as much as digits as its factorization.

1991744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31133 (or 31123 counting only the distinct ones).

The product of its digits is 9072, while the sum is 35.

The square root of 1991744 is about 1411.2916070040. The cubic root of 1991744 is about 125.8185007540.

The spelling of 1991744 in words is "one million, nine hundred ninety-one thousand, seven hundred forty-four".