123120505 has 4 divisors (see below), whose sum is σ = 147744612. Its totient is φ = 98496400.

The previous prime is 123120479. The next prime is 123120521. The reversal of 123120505 is 505021321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505021321 = 7 ⋅72145903.

It can be written as a sum of positive squares in 2 ways, for example, as 40819321 + 82301184 = 6389^2 + 9072^2 .

It is not a de Polignac number, because 123120505 - 2¹³ = 123112313 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 12312046 + ... + 12312055.

It is an arithmetic number, because the mean of its divisors is an integer number (36936153).

Almost surely, 2^123120505 is an apocalyptic number.

It is an amenable number.

123120505 is a deficient number, since it is larger than the sum of its proper divisors (24624107).

123120505 is an equidigital number, since it uses as much as digits as its factorization.

123120505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24624106.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 123120505 is about 11095.9679613813. The cubic root of 123120505 is about 497.4813406804.

Adding to 123120505 its reverse (505021321), we get a palindrome (628141826).

It can be divided in two parts, 1231 and 20505, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 123120505 in words is "one hundred twenty-three million, one hundred twenty thousand, five hundred five".