1281259453840 has 20 divisors (see below), whose sum is σ = 2978928230364. Its totient is φ = 512503781504.

The previous prime is 1281259453823. The next prime is 1281259453883. The reversal of 1281259453840 is 483549521821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 350790860176 + 930468593664 = 592276^2 + 964608^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8007871507 + ... + 8007871666.

Almost surely, 2^{1281259453840} is an apocalyptic number.

1281259453840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1281259453840 is an abundant number, since it is smaller than the sum of its proper divisors (1697668776524).

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

1281259453840 is a wasteful number, since it uses less digits than its factorization.

1281259453840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16015743186 (or 16015743180 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 52.

The spelling of 1281259453840 in words is "one trillion, two hundred eighty-one billion, two hundred fifty-nine million, four hundred fifty-three thousand, eight hundred forty".