1720128 has 84 divisors (see below), whose sum is σ = 4990592. Its totient is φ = 522240.

The previous prime is 1720123. The next prime is 1720133. The reversal of 1720128 is 8210271.

It is an interprime number because it is at equal distance from previous prime (1720123) and next prime (1720133).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720123) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55473 + ... + 55503.

2^1720128 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 1720128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2495296).

1720128 is an abundant number, since it is smaller than the sum of its proper divisors (3270464).

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

1720128 is a wasteful number, since it uses less digits than its factorization.

1720128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 1720128 is about 1311.5365034950. The cubic root of 1720128 is about 119.8175003675.

Adding to 1720128 its reverse (8210271), we get a palindrome (9930399).

The spelling of 1720128 in words is "one million, seven hundred twenty thousand, one hundred twenty-eight".