131031231221 has 16 divisors (see below), whose sum is σ = 143364765120. Its totient is φ = 118768446720.

The previous prime is 131031231203. The next prime is 131031231277. The reversal of 131031231221 is 122132130131.

It is a happy number.

It is not a de Polignac number, because 131031231221 - 2⁶ = 131031231157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 131031231193 and 131031231202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131031230221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5793491 + ... + 5816063.

It is an arithmetic number, because the mean of its divisors is an integer number (8960297820).

Almost surely, 2^131031231221 is an apocalyptic number.

131031231221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

131031231221 is a deficient number, since it is larger than the sum of its proper divisors (12333533899).

131031231221 is a wasteful number, since it uses less digits than its factorization.

131031231221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24116.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 131031231221 its reverse (122132130131), we get a palindrome (253163361352).

The spelling of 131031231221 in words is "one hundred thirty-one billion, thirty-one million, two hundred thirty-one thousand, two hundred twenty-one".