28961280 has 160 divisors (see below), whose sum is σ = 103118400. Its totient is φ = 7704576.

The previous prime is 28961243. The next prime is 28961281. The reversal of 28961280 is 8216982.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28961281) 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, 68911 + ... + 69329.

It is an arithmetic number, because the mean of its divisors is an integer number (644490).

Almost surely, 2^28961280 is an apocalyptic number.

28961280 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 28961280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51559200).

28961280 is an abundant number, since it is smaller than the sum of its proper divisors (74157120).

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

28961280 is an equidigital number, since it uses as much as digits as its factorization.

28961280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 28961280 is about 5381.5685445788. The cubic root of 28961280 is about 307.0948859124.

It can be divided in two parts, 28961 and 280, that added together give a square (29241 = 171²).

The spelling of 28961280 in words is "twenty-eight million, nine hundred sixty-one thousand, two hundred eighty".