13531020321 has 48 divisors (see below), whose sum is σ = 22641638400. Its totient is φ = 7036585920.

The previous prime is 13531020311. The next prime is 13531020329. The reversal of 13531020321 is 12302013531.

It is not a de Polignac number, because 13531020321 - 2¹⁰ = 13531019297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (13531020329) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 225130 + ... + 278828.

It is an arithmetic number, because the mean of its divisors is an integer number (471700800).

Almost surely, 2^13531020321 is an apocalyptic number.

It is an amenable number.

13531020321 is a deficient number, since it is larger than the sum of its proper divisors (9110618079).

13531020321 is a wasteful number, since it uses less digits than its factorization.

13531020321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53806 (or 53793 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 21.

Adding to 13531020321 its reverse (12302013531), we get a palindrome (25833033852).

The spelling of 13531020321 in words is "thirteen billion, five hundred thirty-one million, twenty thousand, three hundred twenty-one".