1321343451520 has 64 divisors (see below), whose sum is σ = 3161126157840. Its totient is φ = 528154306560.

The previous prime is 1321343451473. The next prime is 1321343451521. The reversal of 1321343451520 is 251543431231.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321343451521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136339 + ... + 1631341.

Almost surely, 2^{1321343451520} is an apocalyptic number.

1321343451520 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 1321343451520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1580563078920).

1321343451520 is an abundant number, since it is smaller than the sum of its proper divisors (1839782706320).

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

1321343451520 is a wasteful number, since it uses less digits than its factorization.

1321343451520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1496403 (or 1496391 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 1321343451520 its reverse (251543431231), we get a palindrome (1572886882751).

The spelling of 1321343451520 in words is "one trillion, three hundred twenty-one billion, three hundred forty-three million, four hundred fifty-one thousand, five hundred twenty".