131231003220 has 72 divisors (see below), whose sum is σ = 398717087496. Its totient is φ = 34937816832.

The previous prime is 131231003213. The next prime is 131231003221. The reversal of 131231003220 is 22300132131.

131231003220 is a `hidden beast` number, since 1 + 31 + 2 + 310 + 0 + 322 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4526329284 + 126704673936 = 67278^2 + 355956^2 .

It is a super-2 number, since 2×131231003220² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 131231003193 and 131231003202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131231003221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 484327 + ... + 705006.

Almost surely, 2^131231003220 is an apocalyptic number.

131231003220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131231003220 is an abundant number, since it is smaller than the sum of its proper divisors (267486084276).

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

131231003220 is a wasteful number, since it uses less digits than its factorization.

131231003220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189961 (or 1189956 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 131231003220 its reverse (22300132131), we get a palindrome (153531135351).

The spelling of 131231003220 in words is "one hundred thirty-one billion, two hundred thirty-one million, three thousand, two hundred twenty".