28345220 has 12 divisors (see below), whose sum is σ = 59525004. Its totient is φ = 11338080.

The previous prime is 28345201. The next prime is 28345231. The reversal of 28345220 is 2254382.

It can be written as a sum of positive squares in 2 ways, for example, as 19571776 + 8773444 = 4424^2 + 2962^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28345220.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 708611 + ... + 708650.

It is an arithmetic number, because the mean of its divisors is an integer number (4960417).

Almost surely, 2^28345220 is an apocalyptic number.

28345220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28345220 is an abundant number, since it is smaller than the sum of its proper divisors (31179784).

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

28345220 is a wasteful number, since it uses less digits than its factorization.

28345220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1417270 (or 1417268 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 28345220 is about 5324.0229150521. The cubic root of 28345220 is about 304.9017689575.

The spelling of 28345220 in words is "twenty-eight million, three hundred forty-five thousand, two hundred twenty".