135998123 has 4 divisors (see below), whose sum is σ = 136435728. Its totient is φ = 135560520.

The previous prime is 135998117. The next prime is 135998129. The reversal of 135998123 is 321899531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 321899531 = 12893 ⋅24967.

It is an interprime number because it is at equal distance from previous prime (135998117) and next prime (135998129).

It is a cyclic number.

It is not a de Polignac number, because 135998123 - 2⁸ = 135997867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135998129) 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, 218336 + ... + 218957.

It is an arithmetic number, because the mean of its divisors is an integer number (34108932).

Almost surely, 2^135998123 is an apocalyptic number.

135998123 is a deficient number, since it is larger than the sum of its proper divisors (437605).

135998123 is an equidigital number, since it uses as much as digits as its factorization.

135998123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437604.

The product of its digits is 58320, while the sum is 41.

The square root of 135998123 is about 11661.8233137019. The cubic root of 135998123 is about 514.2539522896.

The spelling of 135998123 in words is "one hundred thirty-five million, nine hundred ninety-eight thousand, one hundred twenty-three".