312201221 has 2 divisors, whose sum is σ = 312201222. Its totient is φ = 312201220.

The previous prime is 312201203. The next prime is 312201223. The reversal of 312201221 is 122102213.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 312052225 + 148996 = 17665^2 + 386^2 .

It is a cyclic number.

It is not a de Polignac number, because 312201221 - 2⁶ = 312201157 is a prime.

Together with 312201223, 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 = 312201196 and 312201205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312201223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156100610 + 156100611.

It is an arithmetic number, because the mean of its divisors is an integer number (156100611).

Almost surely, 2^312201221 is an apocalyptic number.

It is an amenable number.

312201221 is a deficient number, since it is larger than the sum of its proper divisors (1).

312201221 is an equidigital number, since it uses as much as digits as its factorization.

312201221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 312201221 is about 17669.2167624940. The cubic root of 312201221 is about 678.3880655925.

Adding to 312201221 its reverse (122102213), we get a palindrome (434303434).

The spelling of 312201221 in words is "three hundred twelve million, two hundred one thousand, two hundred twenty-one".