131211223231220 has 96 divisors (see below), whose sum is σ = 302601170995200. Its totient is φ = 47394448848000.

The previous prime is 131211223231219. The next prime is 131211223231243. The reversal of 131211223231220 is 22132322112131.

It is a self number, because there is not a number n which added to its sum of digits gives 131211223231220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 625726751 + ... + 625936409.

It is an arithmetic number, because the mean of its divisors is an integer number (3152095531200).

Almost surely, 2^{131211223231220} is an apocalyptic number.

131211223231220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131211223231220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151300585497600).

131211223231220 is an abundant number, since it is smaller than the sum of its proper divisors (171389947763980).

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

131211223231220 is a wasteful number, since it uses less digits than its factorization.

131211223231220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228669 (or 228667 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

Adding to 131211223231220 its reverse (22132322112131), we get a palindrome (153343545343351).

The spelling of 131211223231220 in words is "one hundred thirty-one trillion, two hundred eleven billion, two hundred twenty-three million, two hundred thirty-one thousand, two hundred twenty".