28557805 has 12 divisors (see below), whose sum is σ = 35096220. Its totient is φ = 22307712.

The previous prime is 28557803. The next prime is 28557827. The reversal of 28557805 is 50875582.

It can be written as a sum of positive squares in 2 ways, for example, as 19236996 + 9320809 = 4386^2 + 3053^2 .

It is not a de Polignac number, because 28557805 - 2¹ = 28557803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28557803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7701 + ... + 10789.

It is an arithmetic number, because the mean of its divisors is an integer number (2924685).

Almost surely, 2^28557805 is an apocalyptic number.

It is an amenable number.

28557805 is a deficient number, since it is larger than the sum of its proper divisors (6538415).

28557805 is an equidigital number, since it uses as much as digits as its factorization.

28557805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3180 (or 3137 counting only the distinct ones).

The product of its (nonzero) digits is 112000, while the sum is 40.

The square root of 28557805 is about 5343.9503178828. The cubic root of 28557805 is about 305.6621108383.

The spelling of 28557805 in words is "twenty-eight million, five hundred fifty-seven thousand, eight hundred five".