1321539840000 has 480 divisors, whose sum is σ = 4891959072000. Its totient is φ = 352401408000.

The previous prime is 1321539839969. The next prime is 1321539840007. The reversal of 1321539840000 is 489351231.

1321539840000 is a `hidden beast` number, since 1 + 3 + 215 + 39 + 8 + 400 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is not an unprimeable number, because it can be changed into a prime (1321539840007) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 34540881 + ... + 34579119.

It is an arithmetic number, because the mean of its divisors is an integer number (10191581400).

Almost surely, 2^{1321539840000} is an apocalyptic number.

1321539840000 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 1321539840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2445979536000).

1321539840000 is an abundant number, since it is smaller than the sum of its proper divisors (3570419232000).

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

1321539840000 is an frugal number, since it uses more digits than its factorization.

1321539840000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38290 (or 38249 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 1321539840000 in words is "one trillion, three hundred twenty-one billion, five hundred thirty-nine million, eight hundred forty thousand".