312420221 has 4 divisors (see below), whose sum is σ = 312742944. Its totient is φ = 312097500.

The previous prime is 312420191. The next prime is 312420257. The reversal of 312420221 is 122024213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312420221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 312420221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312422221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159905 + ... + 161846.

It is an arithmetic number, because the mean of its divisors is an integer number (78185736).

Almost surely, 2^312420221 is an apocalyptic number.

It is an amenable number.

312420221 is a deficient number, since it is larger than the sum of its proper divisors (322723).

312420221 is an equidigital number, since it uses as much as digits as its factorization.

312420221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322722.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 312420221 is about 17675.4128947530. The cubic root of 312420221 is about 678.5466516277.

Adding to 312420221 its reverse (122024213), we get a palindrome (434444434).

The spelling of 312420221 in words is "three hundred twelve million, four hundred twenty thousand, two hundred twenty-one".