28133540 has 12 divisors (see below), whose sum is σ = 59080476. Its totient is φ = 11253408.

The previous prime is 28133527. The next prime is 28133557. The reversal of 28133540 is 4533182.

It can be written as a sum of positive squares in 2 ways, for example, as 22335076 + 5798464 = 4726^2 + 2408^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 703319 + ... + 703358.

It is an arithmetic number, because the mean of its divisors is an integer number (4923373).

Almost surely, 2^28133540 is an apocalyptic number.

28133540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28133540 is an abundant number, since it is smaller than the sum of its proper divisors (30946936).

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

28133540 is a wasteful number, since it uses less digits than its factorization.

28133540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1406686 (or 1406684 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 28133540 is about 5304.1059567094. The cubic root of 28133540 is about 304.1408771112.

The spelling of 28133540 in words is "twenty-eight million, one hundred thirty-three thousand, five hundred forty".