312333221 has 2 divisors, whose sum is σ = 312333222. Its totient is φ = 312333220.

The previous prime is 312333199. The next prime is 312333223. The reversal of 312333221 is 122333213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 285136996 + 27196225 = 16886^2 + 5215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312333221 is a prime.

Together with 312333223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 312333193 and 312333202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312333223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156166610 + 156166611.

It is an arithmetic number, because the mean of its divisors is an integer number (156166611).

Almost surely, 2^312333221 is an apocalyptic number.

It is an amenable number.

312333221 is a deficient number, since it is larger than the sum of its proper divisors (1).

312333221 is an equidigital number, since it uses as much as digits as its factorization.

312333221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 20.

The square root of 312333221 is about 17672.9516776344. The cubic root of 312333221 is about 678.4836605713.

Adding to 312333221 its reverse (122333213), we get a palindrome (434666434).

The spelling of 312333221 in words is "three hundred twelve million, three hundred thirty-three thousand, two hundred twenty-one".