131021220404020 has 24 divisors (see below), whose sum is σ = 284632306396200. Its totient is φ = 50601298914432.

The previous prime is 131021220403951. The next prime is 131021220404021. The reversal of 131021220404020 is 20404022120131.

It can be written as a sum of positive squares in 4 ways, for example, as 25098055961616 + 105923164442404 = 5009796^2 + 10291898^2 .

It is a junction number, because it is equal to n+sod(n) for n = 131021220403982 and 131021220404000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131021220404021) 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, 112949327355 + ... + 112949328514.

It is an arithmetic number, because the mean of its divisors is an integer number (11859679433175).

Almost surely, 2^{131021220404020} is an apocalyptic number.

131021220404020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131021220404020 is an abundant number, since it is smaller than the sum of its proper divisors (153611085992180).

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

131021220404020 is a wasteful number, since it uses less digits than its factorization.

131021220404020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225898655907 (or 225898655905 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 131021220404020 its reverse (20404022120131), we get a palindrome (151425242524151).

The spelling of 131021220404020 in words is "one hundred thirty-one trillion, twenty-one billion, two hundred twenty million, four hundred four thousand, twenty".