231808131 has 6 divisors (see below), whose sum is σ = 334833980. Its totient is φ = 154538748.

The previous prime is 231808121. The next prime is 231808133. The reversal of 231808131 is 131808132.

It is not a de Polignac number, because 231808131 - 2⁶ = 231808067 is a prime.

It is a super-2 number, since 2×231808131² = 107470019195426322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231808095 and 231808104.

It is not an unprimeable number, because it can be changed into a prime (231808133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12878221 + ... + 12878238.

Almost surely, 2^231808131 is an apocalyptic number.

231808131 is a deficient number, since it is larger than the sum of its proper divisors (103025849).

231808131 is a wasteful number, since it uses less digits than its factorization.

231808131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25756465 (or 25756462 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 231808131 is about 15225.2465004676. The cubic root of 231808131 is about 614.2939269370.

Subtracting from 231808131 its reverse (131808132), we obtain a palindrome (99999999).

The spelling of 231808131 in words is "two hundred thirty-one million, eight hundred eight thousand, one hundred thirty-one".