28881660 has 48 divisors (see below), whose sum is σ = 81226656. Its totient is φ = 7667712.

The previous prime is 28881659. The next prime is 28881673. The reversal of 28881660 is 6618882.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14484 + ... + 16356.

It is an arithmetic number, because the mean of its divisors is an integer number (1692222).

Almost surely, 2^28881660 is an apocalyptic number.

28881660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28881660 is an abundant number, since it is smaller than the sum of its proper divisors (52344996).

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

28881660 is a wasteful number, since it uses less digits than its factorization.

28881660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2142 (or 2140 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 39.

The square root of 28881660 is about 5374.1659818059. The cubic root of 28881660 is about 306.8132071123.

The spelling of 28881660 in words is "twenty-eight million, eight hundred eighty-one thousand, six hundred sixty".