231513521220331 has 24 divisors (see below), whose sum is σ = 271560520315392. Its totient is φ = 193239671209200.

The previous prime is 231513521220323. The next prime is 231513521220349. The reversal of 231513521220331 is 133022125315132.

It is not a de Polignac number, because 231513521220331 - 2³ = 231513521220323 is a prime.

It is a super-2 number, since 2×231513521220331² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (231513521220301) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29467726 + ... + 36487996.

It is an arithmetic number, because the mean of its divisors is an integer number (11315021679808).

Almost surely, 2^{231513521220331} is an apocalyptic number.

231513521220331 is a deficient number, since it is larger than the sum of its proper divisors (40046999095061).

231513521220331 is an frugal number, since it uses more digits than its factorization.

231513521220331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7020983 (or 7020652 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 34.

Adding to 231513521220331 its reverse (133022125315132), we get a palindrome (364535646535463).

The spelling of 231513521220331 in words is "two hundred thirty-one trillion, five hundred thirteen billion, five hundred twenty-one million, two hundred twenty thousand, three hundred thirty-one".