28857680 has 40 divisors (see below), whose sum is σ = 67609512. Its totient is φ = 11454464.

The previous prime is 28857643. The next prime is 28857701. The reversal of 28857680 is 8675882.

It can be written as a sum of positive squares in 4 ways, for example, as 937024 + 27920656 = 968^2 + 5284^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9644 + ... + 12276.

Almost surely, 2^28857680 is an apocalyptic number.

28857680 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 28857680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33804756).

28857680 is an abundant number, since it is smaller than the sum of its proper divisors (38751832).

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

28857680 is a wasteful number, since it uses less digits than its factorization.

28857680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2783 (or 2777 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 28857680 is about 5371.9344746562. The cubic root of 28857680 is about 306.7282694980.

The spelling of 28857680 in words is "twenty-eight million, eight hundred fifty-seven thousand, six hundred eighty".