28404320 has 72 divisors (see below), whose sum is σ = 78082704. Its totient is φ = 9735936.

The previous prime is 28404319. The next prime is 28404329. The reversal of 28404320 is 2340482.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28404329) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 6029 + ... + 9651.

It is an arithmetic number, because the mean of its divisors is an integer number (1084482).

Almost surely, 2^28404320 is an apocalyptic number.

28404320 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 28404320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39041352).

28404320 is an abundant number, since it is smaller than the sum of its proper divisors (49678384).

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

28404320 is a wasteful number, since it uses less digits than its factorization.

28404320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3652 (or 3637 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

The square root of 28404320 is about 5329.5703391549. The cubic root of 28404320 is about 305.1135293566.

The spelling of 28404320 in words is "twenty-eight million, four hundred four thousand, three hundred twenty".