28581330 has 32 divisors (see below), whose sum is σ = 69004224. Its totient is φ = 7576256.

The previous prime is 28581317. The next prime is 28581337. The reversal of 28581330 is 3318582.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (28581337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2437 + ... + 7943.

It is an arithmetic number, because the mean of its divisors is an integer number (2156382).

Almost surely, 2^28581330 is an apocalyptic number.

28581330 is an abundant number, since it is smaller than the sum of its proper divisors (40422894).

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

28581330 is a wasteful number, since it uses less digits than its factorization.

28581330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5690.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 28581330 is about 5346.1509518531. The cubic root of 28581330 is about 305.7460193363.

The spelling of 28581330 in words is "twenty-eight million, five hundred eighty-one thousand, three hundred thirty".