123121231 has 4 divisors (see below), whose sum is σ = 128474352. Its totient is φ = 117768112.

The previous prime is 123121217. The next prime is 123121249. The reversal of 123121231 is 132121321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 132121321 = 229 ⋅576949.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123121231 is a prime.

It is a super-2 number, since 2×123121231² = 30317675045910722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123121261) 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, 2676526 + ... + 2676571.

It is an arithmetic number, because the mean of its divisors is an integer number (32118588).

Almost surely, 2^123121231 is an apocalyptic number.

123121231 is a deficient number, since it is larger than the sum of its proper divisors (5353121).

123121231 is an equidigital number, since it uses as much as digits as its factorization.

123121231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5353120.

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

The square root of 123121231 is about 11096.0006759192. Note that the first 3 decimals coincide. The cubic root of 123121231 is about 497.4823185050.

Adding to 123121231 its reverse (132121321), we get a palindrome (255242552).

The spelling of 123121231 in words is "one hundred twenty-three million, one hundred twenty-one thousand, two hundred thirty-one".