1281038320800 has 1728 divisors, whose sum is σ = 5635139328000. Its totient is φ = 273118003200.

The previous prime is 1281038320787. The next prime is 1281038320811. The reversal of 1281038320800 is 80238301821.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 2220170112 + ... + 2220170688.

It is an arithmetic number, because the mean of its divisors is an integer number (3261076000).

Almost surely, 2^{1281038320800} is an apocalyptic number.

1281038320800 is a gapful number since it is divisible by the number (10) 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 1281038320800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2817569664000).

1281038320800 is an abundant number, since it is smaller than the sum of its proper divisors (4354101007200).

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

1281038320800 is a wasteful number, since it uses less digits than its factorization.

1281038320800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684 (or 654 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 1281038320800 in words is "one trillion, two hundred eighty-one billion, thirty-eight million, three hundred twenty thousand, eight hundred".