28768640 has 64 divisors (see below), whose sum is σ = 69768000. Its totient is φ = 11341824.

The previous prime is 28768639. The next prime is 28768657. The reversal of 28768640 is 4686782.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50276 + ... + 50844.

It is an arithmetic number, because the mean of its divisors is an integer number (1090125).

Almost surely, 2^28768640 is an apocalyptic number.

28768640 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 28768640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34884000).

28768640 is an abundant number, since it is smaller than the sum of its proper divisors (40999360).

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

28768640 is an equidigital number, since it uses as much as digits as its factorization.

28768640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 41.

The square root of 28768640 is about 5363.6405546979. The cubic root of 28768640 is about 306.4124757740.

The spelling of 28768640 in words is "twenty-eight million, seven hundred sixty-eight thousand, six hundred forty".