312223212121 has 4 divisors (see below), whose sum is σ = 312589242532. Its totient is φ = 311857181712.

The previous prime is 312223212107. The next prime is 312223212143. The reversal of 312223212121 is 121212322213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121212322213 = 47 ⋅2578985579.

It can be written as a sum of positive squares in 2 ways, for example, as 179319218521 + 132903993600 = 423461^2 + 364560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312223212121 is a prime.

It is a super-2 number, since 2×312223212121² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312223212092 and 312223212101.

It is not an unprimeable number, because it can be changed into a prime (312223212221) 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, 183013926 + ... + 183015631.

It is an arithmetic number, because the mean of its divisors is an integer number (78147310633).

Almost surely, 2^312223212121 is an apocalyptic number.

It is an amenable number.

312223212121 is a deficient number, since it is larger than the sum of its proper divisors (366030411).

312223212121 is an equidigital number, since it uses as much as digits as its factorization.

312223212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366030410.

The product of its digits is 576, while the sum is 22.

Adding to 312223212121 its reverse (121212322213), we get a palindrome (433435534334).

The spelling of 312223212121 in words is "three hundred twelve billion, two hundred twenty-three million, two hundred twelve thousand, one hundred twenty-one".