28118500 has 24 divisors (see below), whose sum is σ = 61411896. Its totient is φ = 11247200.

The previous prime is 28118479. The next prime is 28118507. The reversal of 28118500 is 581182.

It can be written as a sum of positive squares in 4 ways, for example, as 1016064 + 27102436 = 1008^2 + 5206^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28118507) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 27619 + ... + 28618.

It is an arithmetic number, because the mean of its divisors is an integer number (2558829).

Almost surely, 2^28118500 is an apocalyptic number.

28118500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28118500 is an abundant number, since it is smaller than the sum of its proper divisors (33293396).

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

28118500 is a wasteful number, since it uses less digits than its factorization.

28118500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56256 (or 56244 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 28118500 is about 5302.6879976103. The cubic root of 28118500 is about 304.0866702326.

Adding to 28118500 its reverse (581182), we get a palindrome (28699682).

It can be divided in two parts, 2811 and 8500, that added together give a palindrome (11311).

The spelling of 28118500 in words is "twenty-eight million, one hundred eighteen thousand, five hundred".