28661860728 has 48 divisors (see below), whose sum is σ = 79277496480. Its totient is φ = 9350676864.

The previous prime is 28661860727. The next prime is 28661860729. The reversal of 28661860728 is 82706816682.

28661860728 is a `hidden beast` number, since 2 + 8 + 6 + 6 + 1 + 8 + 607 + 28 = 666.

It is an interprime number because it is at equal distance from previous prime (28661860727) and next prime (28661860729).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661860727) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4231525 + ... + 4238292.

It is an arithmetic number, because the mean of its divisors is an integer number (1651614510).

Almost surely, 2^28661860728 is an apocalyptic number.

It is an amenable number.

28661860728 is an abundant number, since it is smaller than the sum of its proper divisors (50615635752).

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

28661860728 is a wasteful number, since it uses less digits than its factorization.

28661860728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8469876 (or 8469869 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 28661860728 in words is "twenty-eight billion, six hundred sixty-one million, eight hundred sixty thousand, seven hundred twenty-eight".