123240121 has 2 divisors, whose sum is σ = 123240122. Its totient is φ = 123240120.

The previous prime is 123240119. The next prime is 123240127. The reversal of 123240121 is 121042321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76125625 + 47114496 = 8725^2 + 6864^2 .

It is a cyclic number.

It is not a de Polignac number, because 123240121 - 2¹ = 123240119 is a prime.

Together with 123240119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 123240095 and 123240104.

It is not a weakly prime, because it can be changed into another prime (123240127) 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 as a sum of consecutive naturals, namely, 61620060 + 61620061.

It is an arithmetic number, because the mean of its divisors is an integer number (61620061).

Almost surely, 2^123240121 is an apocalyptic number.

It is an amenable number.

123240121 is a deficient number, since it is larger than the sum of its proper divisors (1).

123240121 is an equidigital number, since it uses as much as digits as its factorization.

123240121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 123240121 is about 11101.3567188880. The cubic root of 123240121 is about 497.6423955415.

Adding to 123240121 its reverse (121042321), we get a palindrome (244282442).

The spelling of 123240121 in words is "one hundred twenty-three million, two hundred forty thousand, one hundred twenty-one".