28666860 has 72 divisors (see below), whose sum is σ = 82731600. Its totient is φ = 7416576.

The previous prime is 28666843. The next prime is 28666903. The reversal of 28666860 is 6866682.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81966 + ... + 82314.

It is an arithmetic number, because the mean of its divisors is an integer number (1149050).

Almost surely, 2^28666860 is an apocalyptic number.

28666860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28666860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41365800).

28666860 is an abundant number, since it is smaller than the sum of its proper divisors (54064740).

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

28666860 is a wasteful number, since it uses less digits than its factorization.

28666860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 28666860 is about 5354.1441893173. The cubic root of 28666860 is about 306.0506985927.

The spelling of 28666860 in words is "twenty-eight million, six hundred sixty-six thousand, eight hundred sixty".