312312221 has 4 divisors (see below), whose sum is σ = 336336252. Its totient is φ = 288288192.

The previous prime is 312312167. The next prime is 312312241. The reversal of 312312221 is 122213213.

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 29702500 + 282609721 = 5450^2 + 16811^2 .

It is a cyclic number.

It is not a de Polignac number, because 312312221 - 2⁶ = 312312157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 312312221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312312241) 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, 12011996 + ... + 12012021.

It is an arithmetic number, because the mean of its divisors is an integer number (84084063).

Almost surely, 2^312312221 is an apocalyptic number.

It is an amenable number.

312312221 is a deficient number, since it is larger than the sum of its proper divisors (24024031).

312312221 is a wasteful number, since it uses less digits than its factorization.

312312221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24024030.

The product of its digits is 144, while the sum is 17.

The square root of 312312221 is about 17672.3575393890. The cubic root of 312312221 is about 678.4684540811.

Adding to 312312221 its reverse (122213213), we get a palindrome (434525434).

It can be divided in two parts, 3123 and 12221, that multiplied together give a palindrome (38166183).

The spelling of 312312221 in words is "three hundred twelve million, three hundred twelve thousand, two hundred twenty-one".