138836018 has 4 divisors (see below), whose sum is σ = 208254030. Its totient is φ = 69418008.

The previous prime is 138836017. The next prime is 138836041. The reversal of 138836018 is 810638831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 810638831 = 14323 ⋅56597.

It can be written as a sum of positive squares in only one way, i.e., 78198649 + 60637369 = 8843^2 + 7787^2 .

It is not an unprimeable number, because it can be changed into a prime (138836017) 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 as a sum of consecutive naturals, namely, 34709003 + ... + 34709006.

Almost surely, 2^138836018 is an apocalyptic number.

138836018 is a deficient number, since it is larger than the sum of its proper divisors (69418012).

138836018 is an equidigital number, since it uses as much as digits as its factorization.

138836018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69418011.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 138836018 is about 11782.8696844190. The cubic root of 138836018 is about 517.8063631277.

The spelling of 138836018 in words is "one hundred thirty-eight million, eight hundred thirty-six thousand, eighteen".