28003890 has 16 divisors (see below), whose sum is σ = 67209408. Its totient is φ = 7467696.

The previous prime is 28003883. The next prime is 28003897. The reversal of 28003890 is 9830082.

It is an interprime number because it is at equal distance from previous prime (28003883) and next prime (28003897).

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 933463 = 28003890 / (2 + 8 + 0 + 0 + 3 + 8 + 9 + 0).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28003897) 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, 466702 + ... + 466761.

It is an arithmetic number, because the mean of its divisors is an integer number (4200588).

Almost surely, 2^28003890 is an apocalyptic number.

28003890 is an abundant number, since it is smaller than the sum of its proper divisors (39205518).

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

28003890 is a wasteful number, since it uses less digits than its factorization.

28003890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933473.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 28003890 is about 5291.8701798136. The cubic root of 28003890 is about 303.6729588353.

The spelling of 28003890 in words is "twenty-eight million, three thousand, eight hundred ninety".