312143221 has 4 divisors (see below), whose sum is σ = 336154252. Its totient is φ = 288132192.

The previous prime is 312143213. The next prime is 312143233. The reversal of 312143221 is 122341213.

It is a happy number.

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 209931121 + 102212100 = 14489^2 + 10110^2 .

It is a cyclic number.

It is not a de Polignac number, because 312143221 - 2³ = 312143213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312143201) 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 3 ways as a sum of consecutive naturals, for example, 12005496 + ... + 12005521.

It is an arithmetic number, because the mean of its divisors is an integer number (84038563).

Almost surely, 2^312143221 is an apocalyptic number.

It is an amenable number.

312143221 is a deficient number, since it is larger than the sum of its proper divisors (24011031).

312143221 is a wasteful number, since it uses less digits than its factorization.

312143221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24011030.

The product of its digits is 288, while the sum is 19.

The square root of 312143221 is about 17667.5754137346. The cubic root of 312143221 is about 678.3460532172.

Adding to 312143221 its reverse (122341213), we get a palindrome (434484434).

The spelling of 312143221 in words is "three hundred twelve million, one hundred forty-three thousand, two hundred twenty-one".