28381085 has 4 divisors (see below), whose sum is σ = 34057308. Its totient is φ = 22704864.

The previous prime is 28381081. The next prime is 28381097. The reversal of 28381085 is 58018382.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21883684 + 6497401 = 4678^2 + 2549^2 .

It is a cyclic number.

It is not a de Polignac number, because 28381085 - 2² = 28381081 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28381081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2838104 + ... + 2838113.

It is an arithmetic number, because the mean of its divisors is an integer number (8514327).

Almost surely, 2^28381085 is an apocalyptic number.

It is an amenable number.

28381085 is a deficient number, since it is larger than the sum of its proper divisors (5676223).

28381085 is an equidigital number, since it uses as much as digits as its factorization.

28381085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5676222.

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 28381085 is about 5327.3900739480. The cubic root of 28381085 is about 305.0303114191.

The spelling of 28381085 in words is "twenty-eight million, three hundred eighty-one thousand, eighty-five".