28740805 has 8 divisors (see below), whose sum is σ = 34599672. Its totient is φ = 22918848.

The previous prime is 28740799. The next prime is 28740851. The reversal of 28740805 is 50804782.

It can be written as a sum of positive squares in 4 ways, for example, as 484 + 28740321 = 22^2 + 5361^2 .

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 28740805 - 2⁵ = 28740773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 7482 + ... + 10651.

It is an arithmetic number, because the mean of its divisors is an integer number (4324959).

Almost surely, 2^28740805 is an apocalyptic number.

It is an amenable number.

28740805 is a deficient number, since it is larger than the sum of its proper divisors (5858867).

28740805 is a wasteful number, since it uses less digits than its factorization.

28740805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18455.

The product of its (nonzero) digits is 17920, while the sum is 34.

The square root of 28740805 is about 5361.0451406419. The cubic root of 28740805 is about 306.3136211013.

The spelling of 28740805 in words is "twenty-eight million, seven hundred forty thousand, eight hundred five".