131131221220 has 48 divisors (see below), whose sum is σ = 285733954800. Its totient is φ = 50508693504.

The previous prime is 131131221217. The next prime is 131131221251. The reversal of 131131221220 is 22122131131.

It can be written as a sum of positive squares in 8 ways, for example, as 6120676 + 131125100544 = 2474^2 + 362112^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 841645 + ... + 985204.

It is an arithmetic number, because the mean of its divisors is an integer number (5952790725).

Almost surely, 2^131131221220 is an apocalyptic number.

131131221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131131221220 is an abundant number, since it is smaller than the sum of its proper divisors (154602733580).

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

131131221220 is a wasteful number, since it uses less digits than its factorization.

131131221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1826992 (or 1826990 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 131131221220 its reverse (22122131131), we get a palindrome (153253352351).

The spelling of 131131221220 in words is "one hundred thirty-one billion, one hundred thirty-one million, two hundred twenty-one thousand, two hundred twenty".