28017720 has 96 divisors (see below), whose sum is σ = 91728000. Its totient is φ = 7416576.

The previous prime is 28017697. The next prime is 28017721. The reversal of 28017720 is 2771082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28017721) 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 23 ways as a sum of consecutive naturals, for example, 80106 + ... + 80454.

It is an arithmetic number, because the mean of its divisors is an integer number (955500).

Almost surely, 2^28017720 is an apocalyptic number.

28017720 is a gapful number since it is divisible by the number (20) 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 28017720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45864000).

28017720 is an abundant number, since it is smaller than the sum of its proper divisors (63710280).

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

28017720 is a wasteful number, since it uses less digits than its factorization.

28017720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 582 counting only the distinct ones).

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

The square root of 28017720 is about 5293.1767399172. The cubic root of 28017720 is about 303.7229412466.

The spelling of 28017720 in words is "twenty-eight million, seventeen thousand, seven hundred twenty".