28003240 has 16 divisors (see below), whose sum is σ = 63007380. Its totient is φ = 11201280.

The previous prime is 28003231. The next prime is 28003249. The reversal of 28003240 is 4230082.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28003231) and next prime (28003249).

It can be written as a sum of positive squares in 2 ways, for example, as 27730756 + 272484 = 5266^2 + 522^2 .

It is not an unprimeable number, because it can be changed into a prime (28003249) 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 3 ways as a sum of consecutive naturals, for example, 350001 + ... + 350080.

Almost surely, 2^28003240 is an apocalyptic number.

28003240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28003240 is an abundant number, since it is smaller than the sum of its proper divisors (35004140).

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

28003240 is a wasteful number, since it uses less digits than its factorization.

28003240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700092 (or 700088 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 28003240 is about 5291.8087644963. The cubic root of 28003240 is about 303.6706092933.

The spelling of 28003240 in words is "twenty-eight million, three thousand, two hundred forty".