312123121 has 4 divisors (see below), whose sum is σ = 313283700. Its totient is φ = 310962544.

The previous prime is 312123109. The next prime is 312123137. The reversal of 312123121 is 121321213.

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 7096896 + 305026225 = 2664^2 + 17465^2 .

It is a cyclic number.

It is not a de Polignac number, because 312123121 - 2¹⁷ = 311992049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 312123095 and 312123104.

It is not an unprimeable number, because it can be changed into a prime (312123101) 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, 579886 + ... + 580423.

It is an arithmetic number, because the mean of its divisors is an integer number (78320925).

Almost surely, 2^312123121 is an apocalyptic number.

It is an amenable number.

312123121 is a deficient number, since it is larger than the sum of its proper divisors (1160579).

312123121 is a wasteful number, since it uses less digits than its factorization.

312123121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1160578.

The product of its digits is 72, while the sum is 16.

The square root of 312123121 is about 17667.0065659126. The cubic root of 312123121 is about 678.3314925418.

Adding to 312123121 its reverse (121321213), we get a palindrome (433444334).

The spelling of 312123121 in words is "three hundred twelve million, one hundred twenty-three thousand, one hundred twenty-one".