231521115511521 has 12 divisors (see below), whose sum is σ = 364821151715280. Its totient is φ = 140315827582680.

The previous prime is 231521115511457. The next prime is 231521115511537. The reversal of 231521115511521 is 125115511125132.

231521115511521 is a `hidden beast` number, since 2 + 3 + 1 + 5 + 2 + 1 + 115 + 5 + 11 + 521 = 666.

It is not a de Polignac number, because 231521115511521 - 2⁶ = 231521115511457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231521115512521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1169298563091 + ... + 1169298563288.

It is an arithmetic number, because the mean of its divisors is an integer number (30401762642940).

Almost surely, 2^{231521115511521} is an apocalyptic number.

It is an amenable number.

231521115511521 is a deficient number, since it is larger than the sum of its proper divisors (133300036203759).

231521115511521 is a wasteful number, since it uses less digits than its factorization.

231521115511521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338597126396 (or 2338597126393 counting only the distinct ones).

The product of its digits is 15000, while the sum is 36.

Adding to 231521115511521 its reverse (125115511125132), we get a palindrome (356636626636653).

The spelling of 231521115511521 in words is "two hundred thirty-one trillion, five hundred twenty-one billion, one hundred fifteen million, five hundred eleven thousand, five hundred twenty-one".