131220320221 has 4 divisors (see below), whose sum is σ = 131224772700. Its totient is φ = 131215867744.

The previous prime is 131220320159. The next prime is 131220320243. The reversal of 131220320221 is 122023022131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1249976025 + 129970344196 = 35355^2 + 360514^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131220320221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131220320321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2181736 + ... + 2241073.

It is an arithmetic number, because the mean of its divisors is an integer number (32806193175).

Almost surely, 2^131220320221 is an apocalyptic number.

It is an amenable number.

131220320221 is a deficient number, since it is larger than the sum of its proper divisors (4452479).

131220320221 is an equidigital number, since it uses as much as digits as its factorization.

131220320221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4452478.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 131220320221 its reverse (122023022131), we get a palindrome (253243342352).

The spelling of 131220320221 in words is "one hundred thirty-one billion, two hundred twenty million, three hundred twenty thousand, two hundred twenty-one".