28042440 has 32 divisors (see below), whose sum is σ = 84127680. Its totient is φ = 7477952.

The previous prime is 28042397. The next prime is 28042447. The reversal of 28042440 is 4424082.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 28042440.

It is not an unprimeable number, because it can be changed into a prime (28042447) 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, 116724 + ... + 116963.

It is an arithmetic number, because the mean of its divisors is an integer number (2628990).

Almost surely, 2^28042440 is an apocalyptic number.

28042440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28042440 is an abundant number, since it is smaller than the sum of its proper divisors (56085240).

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

28042440 is a wasteful number, since it uses less digits than its factorization.

28042440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233701 (or 233697 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

The square root of 28042440 is about 5295.5113067578. The cubic root of 28042440 is about 303.8122397819.

It can be divided in two parts, 28042 and 440, that added together give a palindrome (28482).

The spelling of 28042440 in words is "twenty-eight million, forty-two thousand, four hundred forty".