312312231221 has 4 divisors (see below), whose sum is σ = 312821713452. Its totient is φ = 311802748992.

The previous prime is 312312231191. The next prime is 312312231227. The reversal of 312312231221 is 122132213213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122132213213 = 168347 ⋅725479.

It can be written as a sum of positive squares in 2 ways, for example, as 7900720996 + 304411510225 = 88886^2 + 551735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312312231221 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 (312312231227) 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 in 3 ways as a sum of consecutive naturals, for example, 254740196 + ... + 254741421.

It is an arithmetic number, because the mean of its divisors is an integer number (78205428363).

Almost surely, 2^312312231221 is an apocalyptic number.

It is an amenable number.

312312231221 is a deficient number, since it is larger than the sum of its proper divisors (509482231).

312312231221 is an equidigital number, since it uses as much as digits as its factorization.

312312231221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509482230.

The product of its digits is 864, while the sum is 23.

Adding to 312312231221 its reverse (122132213213), we get a palindrome (434444444434).

The spelling of 312312231221 in words is "three hundred twelve billion, three hundred twelve million, two hundred thirty-one thousand, two hundred twenty-one".