28505860 has 12 divisors (see below), whose sum is σ = 59862348. Its totient is φ = 11402336.

The previous prime is 28505857. The next prime is 28505881. The reversal of 28505860 is 6850582.

It can be written as a sum of positive squares in 2 ways, for example, as 5924356 + 22581504 = 2434^2 + 4752^2 .

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 3 ways as a sum of consecutive naturals, for example, 712627 + ... + 712666.

It is an arithmetic number, because the mean of its divisors is an integer number (4988529).

Almost surely, 2^28505860 is an apocalyptic number.

28505860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28505860 is an abundant number, since it is smaller than the sum of its proper divisors (31356488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28505860 is a wasteful number, since it uses less digits than its factorization.

28505860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1425302 (or 1425300 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 28505860 is about 5339.0879370919. The cubic root of 28505860 is about 305.4766711087.

The spelling of 28505860 in words is "twenty-eight million, five hundred five thousand, eight hundred sixty".