28040320 has 128 divisors (see below), whose sum is σ = 83721600. Its totient is φ = 8724480.

The previous prime is 28040279. The next prime is 28040323. The reversal of 28040320 is 2304082.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (28040323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48996 + ... + 49564.

It is an arithmetic number, because the mean of its divisors is an integer number (654075).

Almost surely, 2^28040320 is an apocalyptic number.

28040320 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 28040320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41860800).

28040320 is an abundant number, since it is smaller than the sum of its proper divisors (55681280).

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

28040320 is a wasteful number, since it uses less digits than its factorization.

28040320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606 (or 594 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 28040320 is about 5295.3111334463. The cubic root of 28040320 is about 303.8045835511.

It can be divided in two parts, 280 and 40320, that multiplied together give a square (11289600 = 3360²).

The spelling of 28040320 in words is "twenty-eight million, forty thousand, three hundred twenty".