8641728 has 70 divisors (see below), whose sum is σ = 25632156. Its totient is φ = 2878848.

The previous prime is 8641709. The next prime is 8641733. The reversal of 8641728 is 8271468.

8641728 is a `hidden beast` number, since 8 + 641 + 7 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 8641692 and 8641701.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4351 + ... + 6017.

Almost surely, 2^8641728 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 8641728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12816078).

8641728 is an abundant number, since it is smaller than the sum of its proper divisors (16990428).

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

8641728 is a wasteful number, since it uses less digits than its factorization.

8641728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1691 (or 1672 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 8641728 is about 2939.6816154135. The cubic root of 8641728 is about 205.2107924969.

It can be divided in two parts, 86 and 41728, that added together give a palindrome (41814).

The spelling of 8641728 in words is "eight million, six hundred forty-one thousand, seven hundred twenty-eight".