212123313121 has 4 divisors (see below), whose sum is σ = 212752759492. Its totient is φ = 211493866752.

The previous prime is 212123313113. The next prime is 212123313179. The reversal of 212123313121 is 121313321212.

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 99200431521 + 112922881600 = 314961^2 + 336040^2 .

It is a cyclic number.

It is not a de Polignac number, because 212123313121 - 2³ = 212123313113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212123313092 and 212123313101.

It is not an unprimeable number, because it can be changed into a prime (212123313221) 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, 314722680 + ... + 314723353.

It is an arithmetic number, because the mean of its divisors is an integer number (53188189873).

Almost surely, 2^212123313121 is an apocalyptic number.

It is an amenable number.

212123313121 is a deficient number, since it is larger than the sum of its proper divisors (629446371).

212123313121 is an equidigital number, since it uses as much as digits as its factorization.

212123313121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629446370.

The product of its digits is 432, while the sum is 22.

Adding to 212123313121 its reverse (121313321212), we get a palindrome (333436634333).

It can be divided in two parts, 21212 and 3313121, that added together give a palindrome (3334333).

The spelling of 212123313121 in words is "two hundred twelve billion, one hundred twenty-three million, three hundred thirteen thousand, one hundred twenty-one".