281268728 has 40 divisors (see below), whose sum is σ = 571789680. Its totient is φ = 129710880.

The previous prime is 281268703. The next prime is 281268787. The reversal of 281268728 is 827862182.

It is a super-2 number, since 2×281268728² = 158224194701475968, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 227873 + ... + 229103.

It is an arithmetic number, because the mean of its divisors is an integer number (14294742).

Almost surely, 2^281268728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 281268728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (285894840).

281268728 is an abundant number, since it is smaller than the sum of its proper divisors (290520952).

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

281268728 is an equidigital number, since it uses as much as digits as its factorization.

281268728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289 (or 1246 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 281268728 is about 16771.0681830347. The cubic root of 281268728 is about 655.1998908205.

The spelling of 281268728 in words is "two hundred eighty-one million, two hundred sixty-eight thousand, seven hundred twenty-eight".