28913920 has 108 divisors (see below), whose sum is σ = 80740044. Its totient is φ = 9891840.

The previous prime is 28913903. The next prime is 28913947. The reversal of 28913920 is 2931982.

It can be written as a sum of positive squares in 2 ways, for example, as 9834496 + 19079424 = 3136^2 + 4368^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62490 + ... + 62950.

It is an arithmetic number, because the mean of its divisors is an integer number (747593).

Almost surely, 2^28913920 is an apocalyptic number.

28913920 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 28913920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40370022).

28913920 is an abundant number, since it is smaller than the sum of its proper divisors (51826124).

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

28913920 is an equidigital number, since it uses as much as digits as its factorization.

28913920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 28913920 is about 5377.1665401027. The cubic root of 28913920 is about 306.9273985075.

The spelling of 28913920 in words is "twenty-eight million, nine hundred thirteen thousand, nine hundred twenty".