28020020 has 48 divisors (see below), whose sum is σ = 67592448. Its totient is φ = 9557760.

The previous prime is 28019993. The next prime is 28020023. The reversal of 28020020 is 2002082.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 28019977 and 28020004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28020023) 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 15 ways as a sum of consecutive naturals, for example, 36440 + ... + 37200.

It is an arithmetic number, because the mean of its divisors is an integer number (1408176).

Almost surely, 2^28020020 is an apocalyptic number.

28020020 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 28020020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33796224).

28020020 is an abundant number, since it is smaller than the sum of its proper divisors (39572428).

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

28020020 is a wasteful number, since it uses less digits than its factorization.

28020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040 (or 1038 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 28020020 is about 5293.3939962939. The cubic root of 28020020 is about 303.7312519829.

The spelling of 28020020 in words is "twenty-eight million, twenty thousand, twenty".