28321280 has 160 divisors (see below), whose sum is σ = 78369984. Its totient is φ = 9732096.

The previous prime is 28321253. The next prime is 28321301. The reversal of 28321280 is 8212382.

It is a tau number, because it is divible by the number of its divisors (160).

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 765422 + ... + 765458.

Almost surely, 2^28321280 is an apocalyptic number.

28321280 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 28321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39184992).

28321280 is an abundant number, since it is smaller than the sum of its proper divisors (50048704).

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

28321280 is a wasteful number, since it uses less digits than its factorization.

28321280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 28321280 is about 5321.7741402656. The cubic root of 28321280 is about 304.8159061054.

The spelling of 28321280 in words is "twenty-eight million, three hundred twenty-one thousand, two hundred eighty".