28491281280 has 2048 divisors, whose sum is σ = 141004800000. Its totient is φ = 5364817920.

The previous prime is 28491281279. The next prime is 28491281281. The reversal of 28491281280 is 8218219482.

28491281280 is a `hidden beast` number, since 2 + 8 + 4 + 91 + 281 + 280 = 666.

It is an interprime number because it is at equal distance from previous prime (28491281279) and next prime (28491281281).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28491281281) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 1238751349 + ... + 1238751371.

It is an arithmetic number, because the mean of its divisors is an integer number (68850000).

Almost surely, 2^28491281280 is an apocalyptic number.

28491281280 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 28491281280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70502400000).

28491281280 is an abundant number, since it is smaller than the sum of its proper divisors (112513518720).

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

28491281280 is a wasteful number, since it uses less digits than its factorization.

28491281280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 45.

The spelling of 28491281280 in words is "twenty-eight billion, four hundred ninety-one million, two hundred eighty-one thousand, two hundred eighty".