13531321531 has 32 divisors (see below), whose sum is σ = 17055449600. Its totient is φ = 10667274912.

The previous prime is 13531321511. The next prime is 13531321579. The reversal of 13531321531 is 13512313531.

It is a happy number.

It is not a de Polignac number, because 13531321531 - 2¹⁷ = 13531190459 is a prime.

It is a super-2 number, since 2×13531321531² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 13531321531.

It is not an unprimeable number, because it can be changed into a prime (13531321511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1256536 + ... + 1267258.

It is an arithmetic number, because the mean of its divisors is an integer number (532982800).

Almost surely, 2^13531321531 is an apocalyptic number.

13531321531 is a deficient number, since it is larger than the sum of its proper divisors (3524128069).

13531321531 is a wasteful number, since it uses less digits than its factorization.

13531321531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11040 (or 11026 counting only the distinct ones).

The product of its digits is 4050, while the sum is 28.

The spelling of 13531321531 in words is "thirteen billion, five hundred thirty-one million, three hundred twenty-one thousand, five hundred thirty-one".