1728720 has 150 divisors (see below), whose sum is σ = 6772818. Its totient is φ = 395136.

The previous prime is 1728697. The next prime is 1728733. The reversal of 1728720 is 278271.

It can be written as a sum of positive squares in only one way, i.e., 1382976 + 345744 = 1176^2 + 588^2 .

It is a nialpdrome in base 14.

It is a zygodrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 246957 + ... + 246963.

2^1728720 is an apocalyptic number.

1728720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1728720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3386409).

1728720 is an abundant number, since it is smaller than the sum of its proper divisors (5044098).

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

1728720 is an equidigital number, since it uses as much as digits as its factorization.

1728720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 1728720 is about 1314.8079707699. The cubic root of 1728720 is about 120.0166643524.

The spelling of 1728720 in words is "one million, seven hundred twenty-eight thousand, seven hundred twenty".