1321320221000 has 192 divisors, whose sum is σ = 3376141488720. Its totient is φ = 481163673600.

The previous prime is 1321320220973. The next prime is 1321320221009. The reversal of 1321320221000 is 1220231231.

It can be written as a sum of positive squares in 24 ways, for example, as 1015995457156 + 305324763844 = 1007966^2 + 552562^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1321320221000.

It is not an unprimeable number, because it can be changed into a prime (1321320221009) 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 47 ways as a sum of consecutive naturals, for example, 69267464 + ... + 69286536.

Almost surely, 2^{1321320221000} is an apocalyptic number.

1321320221000 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 1321320221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1688070744360).

1321320221000 is an abundant number, since it is smaller than the sum of its proper divisors (2054821267720).

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

1321320221000 is a wasteful number, since it uses less digits than its factorization.

1321320221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19253 (or 19166 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 1321320221000 its reverse (1220231231), we get a palindrome (1322540452231).

The spelling of 1321320221000 in words is "one trillion, three hundred twenty-one billion, three hundred twenty million, two hundred twenty-one thousand".