28500040 has 64 divisors (see below), whose sum is σ = 67392000. Its totient is φ = 10832640.

The previous prime is 28500029. The next prime is 28500047. The reversal of 28500040 is 4000582.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 28499990 and 28500017.

It is not an unprimeable number, because it can be changed into a prime (28500047) 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, 91485 + ... + 91795.

It is an arithmetic number, because the mean of its divisors is an integer number (1053000).

Almost surely, 2^28500040 is an apocalyptic number.

28500040 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 28500040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33696000).

28500040 is an abundant number, since it is smaller than the sum of its proper divisors (38891960).

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

28500040 is a wasteful number, since it uses less digits than its factorization.

28500040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 426 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 28500040 is about 5338.5428723576. The cubic root of 28500040 is about 305.4558801177.

The spelling of 28500040 in words is "twenty-eight million, five hundred thousand, forty".