138632218 has 16 divisors (see below), whose sum is σ = 210351744. Its totient is φ = 68519520.

The previous prime is 138632213. The next prime is 138632231. The reversal of 138632218 is 812236831.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (138632213) 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 7 ways as a sum of consecutive naturals, for example, 73321 + ... + 75187.

It is an arithmetic number, because the mean of its divisors is an integer number (13146984).

Almost surely, 2^138632218 is an apocalyptic number.

138632218 is a deficient number, since it is larger than the sum of its proper divisors (71719526).

138632218 is a wasteful number, since it uses less digits than its factorization.

138632218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2277.

The product of its digits is 13824, while the sum is 34.

The square root of 138632218 is about 11774.2183604688. The cubic root of 138632218 is about 517.5528731558.

The spelling of 138632218 in words is "one hundred thirty-eight million, six hundred thirty-two thousand, two hundred eighteen".