131321220 has 24 divisors (see below), whose sum is σ = 367699584. Its totient is φ = 35018976.

The previous prime is 131321173. The next prime is 131321221. The reversal of 131321220 is 22123131.

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 131321220.

It is not an unprimeable number, because it can be changed into a prime (131321221) 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, 1094284 + ... + 1094403.

It is an arithmetic number, because the mean of its divisors is an integer number (15320816).

Almost surely, 2^131321220 is an apocalyptic number.

131321220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131321220 is an abundant number, since it is smaller than the sum of its proper divisors (236378364).

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

131321220 is a wasteful number, since it uses less digits than its factorization.

131321220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188699 (or 2188697 counting only the distinct ones).

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

The square root of 131321220 is about 11459.5471114700. The cubic root of 131321220 is about 508.2900827366.

Adding to 131321220 its reverse (22123131), we get a palindrome (153444351).

The spelling of 131321220 in words is "one hundred thirty-one million, three hundred twenty-one thousand, two hundred twenty".