131231321220 has 24 divisors (see below), whose sum is σ = 367447699584. Its totient is φ = 34995018976.

The previous prime is 131231321219. The next prime is 131231321227. The reversal of 131231321220 is 22123132131.

131231321220 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (131231321227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1093594284 + ... + 1093594403.

It is an arithmetic number, because the mean of its divisors is an integer number (15310320816).

Almost surely, 2^131231321220 is an apocalyptic number.

131231321220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131231321220 is an abundant number, since it is smaller than the sum of its proper divisors (236216378364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131231321220 is a wasteful number, since it uses less digits than its factorization.

131231321220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2187188699 (or 2187188697 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 131231321220 its reverse (22123132131), we get a palindrome (153354453351).

The spelling of 131231321220 in words is "one hundred thirty-one billion, two hundred thirty-one million, three hundred twenty-one thousand, two hundred twenty".