28420000 has 180 divisors, whose sum is σ = 84137130. Its totient is φ = 9408000.

The previous prime is 28419967. The next prime is 28420027. The reversal of 28420000 is 2482.

It can be written as a sum of positive squares in 5 ways, for example, as 414736 + 28005264 = 644^2 + 5292^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 979986 + ... + 980014.

Almost surely, 2^28420000 is an apocalyptic number.

28420000 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 28420000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42068565).

28420000 is an abundant number, since it is smaller than the sum of its proper divisors (55717130).

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

28420000 is an equidigital number, since it uses as much as digits as its factorization.

28420000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 28420000 is about 5331.0411741047. The cubic root of 28420000 is about 305.1696628376.

Adding to 28420000 its reverse (2482), we get a palindrome (28422482).

The spelling of 28420000 in words is "twenty-eight million, four hundred twenty thousand".