1281445728 has 96 divisors (see below), whose sum is σ = 3586060800. Its totient is φ = 399499776.

The previous prime is 1281445699. The next prime is 1281445769. The reversal of 1281445728 is 8275441821.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×1281445728³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1281445728.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139650 + ... + 148542.

It is an arithmetic number, because the mean of its divisors is an integer number (37354800).

Almost surely, 2^1281445728 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 1281445728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1793030400).

1281445728 is an abundant number, since it is smaller than the sum of its proper divisors (2304615072).

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

1281445728 is a wasteful number, since it uses less digits than its factorization.

1281445728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9004 (or 8996 counting only the distinct ones).

The product of its digits is 143360, while the sum is 42.

The square root of 1281445728 is about 35797.2866010819. The cubic root of 1281445728 is about 1086.1756750764.

The spelling of 1281445728 in words is "one billion, two hundred eighty-one million, four hundred forty-five thousand, seven hundred twenty-eight".