28422840 has 128 divisors (see below), whose sum is σ = 89812800. Its totient is φ = 7188480.

The previous prime is 28422839. The next prime is 28422847. The reversal of 28422840 is 4822482.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28422798 and 28422807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28422847) 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 31 ways as a sum of consecutive naturals, for example, 260706 + ... + 260814.

Almost surely, 2^28422840 is an apocalyptic number.

28422840 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 28422840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44906400).

28422840 is an abundant number, since it is smaller than the sum of its proper divisors (61389960).

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

28422840 is a wasteful number, since it uses less digits than its factorization.

28422840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 30.

The square root of 28422840 is about 5331.3075319287. The cubic root of 28422840 is about 305.1798276625.

The spelling of 28422840 in words is "twenty-eight million, four hundred twenty-two thousand, eight hundred forty".