131020131221 has 12 divisors (see below), whose sum is σ = 152431348032. Its totient is φ = 112288103928.

The previous prime is 131020131217. The next prime is 131020131233. The reversal of 131020131221 is 122131020131.

It is not a de Polignac number, because 131020131221 - 2² = 131020131217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 131020131221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131020131521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 205316 + ... + 551538.

It is an arithmetic number, because the mean of its divisors is an integer number (12702612336).

Almost surely, 2^131020131221 is an apocalyptic number.

It is an amenable number.

131020131221 is a deficient number, since it is larger than the sum of its proper divisors (21411216811).

131020131221 is an equidigital number, since it uses as much as digits as its factorization.

131020131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353960 (or 353953 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 131020131221 its reverse (122131020131), we get a palindrome (253151151352).

The spelling of 131020131221 in words is "one hundred thirty-one billion, twenty million, one hundred thirty-one thousand, two hundred twenty-one".