312221121181 has 2 divisors, whose sum is σ = 312221121182. Its totient is φ = 312221121180.

The previous prime is 312221121143. The next prime is 312221121209. The reversal of 312221121181 is 181121122213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 283698977956 + 28522143225 = 532634^2 + 168885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312221121181 is a prime.

It is a super-2 number, since 2×312221121181² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312221121481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156110560590 + 156110560591.

It is an arithmetic number, because the mean of its divisors is an integer number (156110560591).

Almost surely, 2^312221121181 is an apocalyptic number.

It is an amenable number.

312221121181 is a deficient number, since it is larger than the sum of its proper divisors (1).

312221121181 is an equidigital number, since it uses as much as digits as its factorization.

312221121181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 25.

Adding to 312221121181 its reverse (181121122213), we get a palindrome (493342243394).

The spelling of 312221121181 in words is "three hundred twelve billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred eighty-one".