131123220 has 24 divisors (see below), whose sum is σ = 367145184. Its totient is φ = 34966176.

The previous prime is 131123203. The next prime is 131123249. The reversal of 131123220 is 22321131.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 131123220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1092634 + ... + 1092753.

It is an arithmetic number, because the mean of its divisors is an integer number (15297716).

Almost surely, 2^131123220 is an apocalyptic number.

131123220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131123220 is an abundant number, since it is smaller than the sum of its proper divisors (236021964).

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

131123220 is a wasteful number, since it uses less digits than its factorization.

131123220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2185399 (or 2185397 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 131123220 is about 11450.9047677465. The cubic root of 131123220 is about 508.0344955599.

Adding to 131123220 its reverse (22321131), we get a palindrome (153444351).

It can be divided in two parts, 1311 and 23220, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 131123220 in words is "one hundred thirty-one million, one hundred twenty-three thousand, two hundred twenty".