28820440 has 64 divisors (see below), whose sum is σ = 74921760. Its totient is φ = 9861120.

The previous prime is 28820431. The next prime is 28820443. The reversal of 28820440 is 4402882.

It is a junction number, because it is equal to n+sod(n) for n = 28820399 and 28820408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28820443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5554 + ... + 9406.

Almost surely, 2^28820440 is an apocalyptic number.

28820440 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 28820440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37460880).

28820440 is an abundant number, since it is smaller than the sum of its proper divisors (46101320).

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

28820440 is a wasteful number, since it uses less digits than its factorization.

28820440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3892 (or 3888 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 28.

The square root of 28820440 is about 5368.4671927842. The cubic root of 28820440 is about 306.5962713866.

The spelling of 28820440 in words is "twenty-eight million, eight hundred twenty thousand, four hundred forty".