28305408 has 96 divisors (see below), whose sum is σ = 80196480. Its totient is φ = 8847360.

The previous prime is 28305397. The next prime is 28305413. The reversal of 28305408 is 80450382.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×28305408² = 1602392244092928, which contains 22 as substring.

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, 104313 + ... + 104583.

It is an arithmetic number, because the mean of its divisors is an integer number (835380).

Almost surely, 2^28305408 is an apocalyptic number.

28305408 is the 3072-nd octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28305408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40098240).

28305408 is an abundant number, since it is smaller than the sum of its proper divisors (51891072).

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

28305408 is a wasteful number, since it uses less digits than its factorization.

28305408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 28305408 is about 5320.2826992557. The cubic root of 28305408 is about 304.7589531460.

The spelling of 28305408 in words is "twenty-eight million, three hundred five thousand, four hundred eight".