28170805 has 16 divisors (see below), whose sum is σ = 37255680. Its totient is φ = 20317248.

The previous prime is 28170797. The next prime is 28170811. The reversal of 28170805 is 50807182.

It is a cyclic number.

It is not a de Polignac number, because 28170805 - 2³ = 28170797 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2245 + ... + 7834.

It is an arithmetic number, because the mean of its divisors is an integer number (2328480).

Almost surely, 2^28170805 is an apocalyptic number.

It is an amenable number.

28170805 is a deficient number, since it is larger than the sum of its proper divisors (9084875).

28170805 is a wasteful number, since it uses less digits than its factorization.

28170805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10140.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 28170805 is about 5307.6176388282. The cubic root of 28170805 is about 304.2751037235.

Adding to 28170805 its reverse (50807182), we get a palindrome (78977987).

The spelling of 28170805 in words is "twenty-eight million, one hundred seventy thousand, eight hundred five".