123120145 has 4 divisors (see below), whose sum is σ = 147744180. Its totient is φ = 98496112.

The previous prime is 123120139. The next prime is 123120149. The reversal of 123120145 is 541021321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 541021321 = 2741 ⋅197381.

It can be written as a sum of positive squares in 2 ways, for example, as 25979409 + 97140736 = 5097^2 + 9856^2 .

It is a cyclic number.

It is not a de Polignac number, because 123120145 - 2⁷ = 123120017 is a prime.

It is not an unprimeable number, because it can be changed into a prime (123120149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12312010 + ... + 12312019.

It is an arithmetic number, because the mean of its divisors is an integer number (36936045).

Almost surely, 2^123120145 is an apocalyptic number.

It is an amenable number.

123120145 is a deficient number, since it is larger than the sum of its proper divisors (24624035).

123120145 is an equidigital number, since it uses as much as digits as its factorization.

123120145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24624034.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 123120145 is about 11095.9517392606. The cubic root of 123120145 is about 497.4808558074.

Adding to 123120145 its reverse (541021321), we get a palindrome (664141466).

The spelling of 123120145 in words is "one hundred twenty-three million, one hundred twenty thousand, one hundred forty-five".