28087940 has 12 divisors (see below), whose sum is σ = 58984716. Its totient is φ = 11235168.

The previous prime is 28087937. The next prime is 28087967. The reversal of 28087940 is 4978082.

It can be written as a sum of positive squares in 2 ways, for example, as 8868484 + 19219456 = 2978^2 + 4384^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28087894 and 28087903.

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, 702179 + ... + 702218.

It is an arithmetic number, because the mean of its divisors is an integer number (4915393).

Almost surely, 2^28087940 is an apocalyptic number.

28087940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28087940 is an abundant number, since it is smaller than the sum of its proper divisors (30896776).

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

28087940 is a wasteful number, since it uses less digits than its factorization.

28087940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404406 (or 1404404 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 28087940 is about 5299.8056568142. The cubic root of 28087940 is about 303.9764668995.

The spelling of 28087940 in words is "twenty-eight million, eighty-seven thousand, nine hundred forty".