28189770 has 64 divisors (see below), whose sum is σ = 77780736. Its totient is φ = 6405120.

The previous prime is 28189751. The next prime is 28189793. The reversal of 28189770 is 7798182.

It is a Harshad number since it is a multiple of its sum of digits (42).

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 31 ways as a sum of consecutive naturals, for example, 50332 + ... + 50888.

It is an arithmetic number, because the mean of its divisors is an integer number (1215324).

Almost surely, 2^28189770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28189770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38890368).

28189770 is an abundant number, since it is smaller than the sum of its proper divisors (49590966).

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

28189770 is a wasteful number, since it uses less digits than its factorization.

28189770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 815.

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 28189770 is about 5309.4039213456. The cubic root of 28189770 is about 304.3433692308.

The spelling of 28189770 in words is "twenty-eight million, one hundred eighty-nine thousand, seven hundred seventy".