28920000 has 140 divisors (see below), whose sum is σ = 96013016. Its totient is φ = 7680000.

The previous prime is 28919987. The next prime is 28920007. The reversal of 28920000 is 2982.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28920007) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 119880 + ... + 120120.

Almost surely, 2^28920000 is an apocalyptic number.

28920000 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 28920000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48006508).

28920000 is an abundant number, since it is smaller than the sum of its proper divisors (67093016).

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

28920000 is an equidigital number, since it uses as much as digits as its factorization.

28920000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 28920000 is about 5377.7318638995. The cubic root of 28920000 is about 306.9489104967.

Adding to 28920000 its reverse (2982), we get a palindrome (28922982).

The spelling of 28920000 in words is "twenty-eight million, nine hundred twenty thousand".