28712660 has 24 divisors (see below), whose sum is σ = 63844200. Its totient is φ = 10809344.

The previous prime is 28712659. The next prime is 28712687. The reversal of 28712660 is 6621782.

It can be written as a sum of positive squares in 4 ways, for example, as 1317904 + 27394756 = 1148^2 + 5234^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41885 + ... + 42564.

It is an arithmetic number, because the mean of its divisors is an integer number (2660175).

Almost surely, 2^28712660 is an apocalyptic number.

28712660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28712660 is an abundant number, since it is smaller than the sum of its proper divisors (35131540).

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

28712660 is a wasteful number, since it uses less digits than its factorization.

28712660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84475 (or 84473 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 28712660 is about 5358.4195431116. The cubic root of 28712660 is about 306.2136005608.

The spelling of 28712660 in words is "twenty-eight million, seven hundred twelve thousand, six hundred sixty".