131181116221 has 2 divisors, whose sum is σ = 131181116222. Its totient is φ = 131181116220.

The previous prime is 131181116207. The next prime is 131181116293. The reversal of 131181116221 is 122611181131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91125496900 + 40055619321 = 301870^2 + 200139^2 .

It is a cyclic number.

It is not a de Polignac number, because 131181116221 - 2¹⁹ = 131180591933 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131181116221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131181116021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65590558110 + 65590558111.

It is an arithmetic number, because the mean of its divisors is an integer number (65590558111).

Almost surely, 2^131181116221 is an apocalyptic number.

It is an amenable number.

131181116221 is a deficient number, since it is larger than the sum of its proper divisors (1).

131181116221 is an equidigital number, since it uses as much as digits as its factorization.

131181116221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 28.

Adding to 131181116221 its reverse (122611181131), we get a palindrome (253792297352).

The spelling of 131181116221 in words is "one hundred thirty-one billion, one hundred eighty-one million, one hundred sixteen thousand, two hundred twenty-one".