312211321 has 4 divisors (see below), whose sum is σ = 312721252. Its totient is φ = 311701392.

The previous prime is 312211309. The next prime is 312211327. The reversal of 312211321 is 123112213.

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 85377600 + 226833721 = 9240^2 + 15061^2 .

It is a cyclic number.

It is not a de Polignac number, because 312211321 - 2¹⁵ = 312178553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312211295 and 312211304.

It is not an unprimeable number, because it can be changed into a prime (312211327) 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, 254046 + ... + 255271.

It is an arithmetic number, because the mean of its divisors is an integer number (78180313).

Almost surely, 2^312211321 is an apocalyptic number.

It is an amenable number.

312211321 is a deficient number, since it is larger than the sum of its proper divisors (509931).

312211321 is an equidigital number, since it uses as much as digits as its factorization.

312211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509930.

The product of its digits is 72, while the sum is 16.

The square root of 312211321 is about 17669.5025679842. The cubic root of 312211321 is about 678.3953810087.

Adding to 312211321 its reverse (123112213), we get a palindrome (435323534).

The spelling of 312211321 in words is "three hundred twelve million, two hundred eleven thousand, three hundred twenty-one".