1321515280800 has 1152 divisors, whose sum is σ = 5735152926720. Its totient is φ = 289399910400.

The previous prime is 1321515280781. The next prime is 1321515280831. The reversal of 1321515280800 is 80825151231.

1321515280800 is a `hidden beast` number, since 1 + 3 + 2 + 1 + 51 + 528 + 0 + 80 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 145169049 + ... + 145178151.

It is an arithmetic number, because the mean of its divisors is an integer number (4978431360).

Almost surely, 2^{1321515280800} is an apocalyptic number.

1321515280800 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 1321515280800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2867576463360).

1321515280800 is an abundant number, since it is smaller than the sum of its proper divisors (4413637645920).

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

1321515280800 is a wasteful number, since it uses less digits than its factorization.

1321515280800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9203 (or 9184 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The spelling of 1321515280800 in words is "one trillion, three hundred twenty-one billion, five hundred fifteen million, two hundred eighty thousand, eight hundred".