28381590 has 80 divisors (see below), whose sum is σ = 78460272. Its totient is φ = 7356096.

The previous prime is 28381589. The next prime is 28381621. The reversal of 28381590 is 9518382.

It is a congruent number.

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 29497 + ... + 30443.

Almost surely, 2^28381590 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28381590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39230136).

28381590 is an abundant number, since it is smaller than the sum of its proper divisors (50078682).

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

28381590 is a wasteful number, since it uses less digits than its factorization.

28381590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003 (or 994 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 28381590 is about 5327.4374703041. The cubic root of 28381590 is about 305.0321205982.

The spelling of 28381590 in words is "twenty-eight million, three hundred eighty-one thousand, five hundred ninety".