28123040 has 144 divisors (see below), whose sum is σ = 79017120. Its totient is φ = 9354240.

The previous prime is 28122977. The next prime is 28123057. The reversal of 28123040 is 4032182.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 969746 + ... + 969774.

It is an arithmetic number, because the mean of its divisors is an integer number (548730).

Almost surely, 2^28123040 is an apocalyptic number.

28123040 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 28123040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39508560).

28123040 is an abundant number, since it is smaller than the sum of its proper divisors (50894080).

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

28123040 is a wasteful number, since it uses less digits than its factorization.

28123040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 28123040 is about 5303.1160651074. The cubic root of 28123040 is about 304.1030352496.

The spelling of 28123040 in words is "twenty-eight million, one hundred twenty-three thousand, forty".