1721984 has 32 divisors (see below), whose sum is σ = 3745440. Its totient is φ = 782080.

The previous prime is 1721983. The next prime is 1722013. The reversal of 1721984 is 4891271.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a nialpdrome in base 8.

It is a self number, because there is not a number n which added to its sum of digits gives 1721984.

It is not an unprimeable number, because it can be changed into a prime (1721983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 797 + ... + 2019.

It is an arithmetic number, because the mean of its divisors is an integer number (117045).

2^1721984 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 1721984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1872720).

1721984 is an abundant number, since it is smaller than the sum of its proper divisors (2023456).

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

1721984 is a wasteful number, since it uses less digits than its factorization.

1721984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248 (or 1236 counting only the distinct ones).

The product of its digits is 4032, while the sum is 32.

The square root of 1721984 is about 1312.2438797724. The cubic root of 1721984 is about 119.8605788179.

The spelling of 1721984 in words is "one million, seven hundred twenty-one thousand, nine hundred eighty-four".