28420140 has 96 divisors (see below), whose sum is σ = 91736064. Its totient is φ = 6439680.

The previous prime is 28420129. The next prime is 28420151. The reversal of 28420140 is 4102482.

It is an interprime number because it is at equal distance from previous prime (28420129) and next prime (28420151).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65725 + ... + 66155.

It is an arithmetic number, because the mean of its divisors is an integer number (955584).

Almost surely, 2^28420140 is an apocalyptic number.

28420140 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 28420140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45868032).

28420140 is an abundant number, since it is smaller than the sum of its proper divisors (63315924).

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

28420140 is a wasteful number, since it uses less digits than its factorization.

28420140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607 (or 605 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 28420140 is about 5331.0543047319. The cubic root of 28420140 is about 305.1701639364.

The spelling of 28420140 in words is "twenty-eight million, four hundred twenty thousand, one hundred forty".