28881680 has 80 divisors (see below), whose sum is σ = 70977600. Its totient is φ = 10913280.

The previous prime is 28881679. The next prime is 28881703. The reversal of 28881680 is 8618882.

It is a tau number, because it is divible by the number of its divisors (80).

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 15 ways as a sum of consecutive naturals, for example, 136775 + ... + 136985.

It is an arithmetic number, because the mean of its divisors is an integer number (887220).

Almost surely, 2^28881680 is an apocalyptic number.

28881680 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 28881680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35488800).

28881680 is an abundant number, since it is smaller than the sum of its proper divisors (42095920).

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

28881680 is a wasteful number, since it uses less digits than its factorization.

28881680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 41.

The square root of 28881680 is about 5374.1678425594. The cubic root of 28881680 is about 306.8132779330.

The spelling of 28881680 in words is "twenty-eight million, eight hundred eighty-one thousand, six hundred eighty".