28186720 has 48 divisors (see below), whose sum is σ = 67223520. Its totient is φ = 11167744.

The previous prime is 28186703. The next prime is 28186723. The reversal of 28186720 is 2768182.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28186723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17301 + ... + 18859.

It is an arithmetic number, because the mean of its divisors is an integer number (1400490).

Almost surely, 2^28186720 is an apocalyptic number.

28186720 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 28186720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33611760).

28186720 is an abundant number, since it is smaller than the sum of its proper divisors (39036800).

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

28186720 is a wasteful number, since it uses less digits than its factorization.

28186720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687 (or 1679 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 28186720 is about 5309.1166873596. The cubic root of 28186720 is about 304.3323926631.

The spelling of 28186720 in words is "twenty-eight million, one hundred eighty-six thousand, seven hundred twenty".