123312121 has 4 divisors (see below), whose sum is σ = 123341812. Its totient is φ = 123282432.

The previous prime is 123312113. The next prime is 123312181. The reversal of 123312121 is 121213321.

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 85008400 + 38303721 = 9220^2 + 6189^2 .

It is a cyclic number.

It is not a de Polignac number, because 123312121 - 2³ = 123312113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123312095 and 123312104.

It is not an unprimeable number, because it can be changed into a prime (123312181) 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, 7356 + ... + 17341.

It is an arithmetic number, because the mean of its divisors is an integer number (30835453).

Almost surely, 2^123312121 is an apocalyptic number.

It is an amenable number.

123312121 is a deficient number, since it is larger than the sum of its proper divisors (29691).

123312121 is an equidigital number, since it uses as much as digits as its factorization.

123312121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29690.

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

The square root of 123312121 is about 11104.5990922680. The cubic root of 123312121 is about 497.7392884386.

Adding to 123312121 its reverse (121213321), we get a palindrome (244525442).

It can be divided in two parts, 12 and 3312121, that added together give a palindrome (3312133).

The spelling of 123312121 in words is "one hundred twenty-three million, three hundred twelve thousand, one hundred twenty-one".