28109540280 has 128 divisors (see below), whose sum is σ = 86192709120. Its totient is φ = 7331980800.

The previous prime is 28109540279. The next prime is 28109540293. The reversal of 28109540280 is 8204590182.

It is a Cunningham number, because it is equal to 167659²-1.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 991989 + ... + 1019931.

It is an arithmetic number, because the mean of its divisors is an integer number (673380540).

Almost surely, 2^28109540280 is an apocalyptic number.

28109540280 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 28109540280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43096354560).

28109540280 is an abundant number, since it is smaller than the sum of its proper divisors (58083168840).

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

28109540280 is a wasteful number, since it uses less digits than its factorization.

28109540280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28141 (or 28137 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 39.

The spelling of 28109540280 in words is "twenty-eight billion, one hundred nine million, five hundred forty thousand, two hundred eighty".