28225920 has 128 divisors (see below), whose sum is σ = 91824480. Its totient is φ = 7372800.

The previous prime is 28225919. The next prime is 28225921. The reversal of 28225920 is 2952282.

It is an interprime number because it is at equal distance from previous prime (28225919) and next prime (28225921).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28225921) 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 15 ways as a sum of consecutive naturals, for example, 117000 + ... + 117240.

Almost surely, 2^28225920 is an apocalyptic number.

28225920 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 28225920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45912240).

28225920 is an abundant number, since it is smaller than the sum of its proper divisors (63598560).

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

28225920 is a wasteful number, since it uses less digits than its factorization.

28225920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 28225920 is about 5312.8071675904. The cubic root of 28225920 is about 304.4734082866.

The spelling of 28225920 in words is "twenty-eight million, two hundred twenty-five thousand, nine hundred twenty".