28109140 has 24 divisors (see below), whose sum is σ = 59197320. Its totient is φ = 11211648.

The previous prime is 28109131. The next prime is 28109141. The reversal of 28109140 is 4190182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1089936 + 27019204 = 1044^2 + 5198^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28109141) 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, 5974 + ... + 9586.

It is an arithmetic number, because the mean of its divisors is an integer number (2466555).

Almost surely, 2^28109140 is an apocalyptic number.

28109140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28109140 is an abundant number, since it is smaller than the sum of its proper divisors (31088180).

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

28109140 is a wasteful number, since it uses less digits than its factorization.

28109140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4011 (or 4009 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 28109140 is about 5301.8053528963. The cubic root of 28109140 is about 304.0529253421.

The spelling of 28109140 in words is "twenty-eight million, one hundred nine thousand, one hundred forty".