138612505 has 16 divisors (see below), whose sum is σ = 176158080. Its totient is φ = 104412672.

The previous prime is 138612503. The next prime is 138612511. The reversal of 138612505 is 505216831.

It is a cyclic number.

It is not a de Polignac number, because 138612505 - 2¹ = 138612503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138612503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11497 + ... + 20233.

It is an arithmetic number, because the mean of its divisors is an integer number (11009880).

Almost surely, 2^138612505 is an apocalyptic number.

It is an amenable number.

138612505 is a deficient number, since it is larger than the sum of its proper divisors (37545575).

138612505 is a wasteful number, since it uses less digits than its factorization.

138612505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8928.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 138612505 is about 11773.3812050744. The cubic root of 138612505 is about 517.5283406107.

The spelling of 138612505 in words is "one hundred thirty-eight million, six hundred twelve thousand, five hundred five".