28389205 has 8 divisors (see below), whose sum is σ = 36687672. Its totient is φ = 20964288.

The previous prime is 28389161. The next prime is 28389209. The reversal of 28389205 is 50298382.

It can be written as a sum of positive squares in 4 ways, for example, as 1203409 + 27185796 = 1097^2 + 5214^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28389205 - 2¹⁵ = 28356437 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 (28389209) 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, 218314 + ... + 218443.

It is an arithmetic number, because the mean of its divisors is an integer number (4585959).

Almost surely, 2^28389205 is an apocalyptic number.

It is an amenable number.

28389205 is a deficient number, since it is larger than the sum of its proper divisors (8298467).

28389205 is a wasteful number, since it uses less digits than its factorization.

28389205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436775.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 28389205 is about 5328.1521186993. The cubic root of 28389205 is about 305.0593989840.

The spelling of 28389205 in words is "twenty-eight million, three hundred eighty-nine thousand, two hundred five".