123231223121 has 4 divisors (see below), whose sum is σ = 123235219044. Its totient is φ = 123227227200.

The previous prime is 123231223117. The next prime is 123231223151. The reversal of 123231223121 is 121322132321.

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 83096710225 + 40134512896 = 288265^2 + 200336^2 .

It is a cyclic number.

It is not a de Polignac number, because 123231223121 - 2² = 123231223117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123231223151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1951340 + ... + 2013501.

It is an arithmetic number, because the mean of its divisors is an integer number (30808804761).

Almost surely, 2^123231223121 is an apocalyptic number.

It is an amenable number.

123231223121 is a deficient number, since it is larger than the sum of its proper divisors (3995923).

123231223121 is an equidigital number, since it uses as much as digits as its factorization.

123231223121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3995922.

The product of its digits is 864, while the sum is 23.

Adding to 123231223121 its reverse (121322132321), we get a palindrome (244553355442).

The spelling of 123231223121 in words is "one hundred twenty-three billion, two hundred thirty-one million, two hundred twenty-three thousand, one hundred twenty-one".