1391984 has 30 divisors (see below), whose sum is σ = 2968560. Its totient is φ = 631840.

The previous prime is 1391981. The next prime is 1391989. The reversal of 1391984 is 4891931.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1391981) 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 5 ways as a sum of consecutive naturals, for example, 1577 + ... + 2295.

It is an arithmetic number, because the mean of its divisors is an integer number (98952).

2^1391984 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 1391984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1484280).

1391984 is an abundant number, since it is smaller than the sum of its proper divisors (1576576).

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

1391984 is a wasteful number, since it uses less digits than its factorization.

1391984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749 (or 732 counting only the distinct ones).

The product of its digits is 7776, while the sum is 35.

The square root of 1391984 is about 1179.8237156457. The cubic root of 1391984 is about 111.6549756330.

The spelling of 1391984 in words is "one million, three hundred ninety-one thousand, nine hundred eighty-four".