28664020 has 72 divisors (see below), whose sum is σ = 76416480. Its totient is φ = 8930880.

The previous prime is 28663939. The next prime is 28664071. The reversal of 28664020 is 2046682.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 28664020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9451 + ... + 12109.

It is an arithmetic number, because the mean of its divisors is an integer number (1061340).

Almost surely, 2^28664020 is an apocalyptic number.

28664020 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 28664020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38208240).

28664020 is an abundant number, since it is smaller than the sum of its proper divisors (47752460).

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

28664020 is a wasteful number, since it uses less digits than its factorization.

28664020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2693 (or 2684 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 28664020 is about 5353.8789676271. The cubic root of 28664020 is about 306.0405915366.

It can be divided in two parts, 2866 and 4020, that added together give a palindrome (6886).

The spelling of 28664020 in words is "twenty-eight million, six hundred sixty-four thousand, twenty".