1720628 has 48 divisors (see below), whose sum is σ = 3857280. Its totient is φ = 653184.

The previous prime is 1720619. The next prime is 1720633. The reversal of 1720628 is 8260271.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a d-powerful number, because it can be written as 1 + 7² + 2 + 0 + 6⁸ + 2¹³ + 8⁵ .

It is a junction number, because it is equal to n+sod(n) for n = 1720597 and 1720606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10475 + ... + 10637.

It is an arithmetic number, because the mean of its divisors is an integer number (80360).

2^1720628 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 1720628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1928640).

1720628 is an abundant number, since it is smaller than the sum of its proper divisors (2136652).

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

1720628 is a wasteful number, since it uses less digits than its factorization.

1720628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 1720628 is about 1311.7271057655. The cubic root of 1720628 is about 119.8291086018.

Adding to 1720628 its reverse (8260271), we get a palindrome (9980899).

The spelling of 1720628 in words is "one million, seven hundred twenty thousand, six hundred twenty-eight".