28003656 has 64 divisors (see below), whose sum is σ = 72576000. Its totient is φ = 8998400.

The previous prime is 28003649. The next prime is 28003667. The reversal of 28003656 is 65630082.

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, 146521 + ... + 146711.

It is an arithmetic number, because the mean of its divisors is an integer number (1134000).

Almost surely, 2^28003656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28003656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36288000).

28003656 is an abundant number, since it is smaller than the sum of its proper divisors (44572344).

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

28003656 is a wasteful number, since it uses less digits than its factorization.

28003656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 28003656 is about 5291.8480703815. The cubic root of 28003656 is about 303.6721130044.

The spelling of 28003656 in words is "twenty-eight million, three thousand, six hundred fifty-six".