28945920 has 80 divisors (see below), whose sum is σ = 92561040. Its totient is φ = 7716864.

The previous prime is 28945913. The next prime is 28945921. The reversal of 28945920 is 2954982.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28945921) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5796 + ... + 9564.

It is an arithmetic number, because the mean of its divisors is an integer number (1157013).

Almost surely, 2^28945920 is an apocalyptic number.

28945920 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 28945920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46280520).

28945920 is an abundant number, since it is smaller than the sum of its proper divisors (63615120).

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

28945920 is an equidigital number, since it uses as much as digits as its factorization.

28945920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3795 (or 3779 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 28945920 is about 5380.1412620860. The cubic root of 28945920 is about 307.0405856927.

The spelling of 28945920 in words is "twenty-eight million, nine hundred forty-five thousand, nine hundred twenty".