312211221 has 8 divisors (see below), whose sum is σ = 475750464. Its totient is φ = 178406400.

The previous prime is 312211183. The next prime is 312211247. The reversal of 312211221 is 122112213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 312211221 - 2⁶ = 312211157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 312211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312212221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7433580 + ... + 7433621.

It is an arithmetic number, because the mean of its divisors is an integer number (59468808).

Almost surely, 2^312211221 is an apocalyptic number.

It is an amenable number.

312211221 is a deficient number, since it is larger than the sum of its proper divisors (163539243).

312211221 is a wasteful number, since it uses less digits than its factorization.

312211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14867211.

The product of its digits is 48, while the sum is 15.

The square root of 312211221 is about 17669.4997382495. The cubic root of 312211221 is about 678.3953085796.

Adding to 312211221 its reverse (122112213), we get a palindrome (434323434).

It can be divided in two parts, 3 and 12211221, that multiplied together give a palindrome (36633663).

The spelling of 312211221 in words is "three hundred twelve million, two hundred eleven thousand, two hundred twenty-one".