1991312 has 20 divisors (see below), whose sum is σ = 4085676. Its totient is φ = 936960.

The previous prime is 1991293. The next prime is 1991351. The reversal of 1991312 is 2131991.

It can be written as a sum of positive squares in 2 ways, for example, as 541696 + 1449616 = 736^2 + 1204^2 .

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, 3389 + ... + 3932.

2^1991312 is an apocalyptic number.

It is an amenable number.

1991312 is an abundant number, since it is smaller than the sum of its proper divisors (2094364).

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

1991312 is a wasteful number, since it uses less digits than its factorization.

1991312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7346 (or 7340 counting only the distinct ones).

The product of its digits is 486, while the sum is 26.

The square root of 1991312 is about 1411.1385474148. The cubic root of 1991312 is about 125.8094036139.

The spelling of 1991312 in words is "one million, nine hundred ninety-one thousand, three hundred twelve".