28328940 has 168 divisors, whose sum is σ = 93648240. Its totient is φ = 7185024.

The previous prime is 28328933. The next prime is 28328941. The reversal of 28328940 is 4982382.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28328895 and 28328904.

It is not an unprimeable number, because it can be changed into a prime (28328941) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 422787 + ... + 422853.

It is an arithmetic number, because the mean of its divisors is an integer number (557430).

Almost surely, 2^28328940 is an apocalyptic number.

28328940 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 28328940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46824120).

28328940 is an abundant number, since it is smaller than the sum of its proper divisors (65319300).

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

28328940 is a wasteful number, since it uses less digits than its factorization.

28328940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 28328940 is about 5322.4937764172. The cubic root of 28328940 is about 304.8433846112.

The spelling of 28328940 in words is "twenty-eight million, three hundred twenty-eight thousand, nine hundred forty".