28003820 has 96 divisors (see below), whose sum is σ = 67568256. Its totient is φ = 9676800.

The previous prime is 28003817. The next prime is 28003823. The reversal of 28003820 is 2830082.

It is an interprime number because it is at equal distance from previous prime (28003817) and next prime (28003823).

It is not an unprimeable number, because it can be changed into a prime (28003823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 394385 + ... + 394455.

It is an arithmetic number, because the mean of its divisors is an integer number (703836).

Almost surely, 2^28003820 is an apocalyptic number.

28003820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28003820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33784128).

28003820 is an abundant number, since it is smaller than the sum of its proper divisors (39564436).

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

28003820 is a wasteful number, since it uses less digits than its factorization.

28003820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 28003820 is about 5291.8635658906. The cubic root of 28003820 is about 303.6727058095.

The spelling of 28003820 in words is "twenty-eight million, three thousand, eight hundred twenty".