138642044 has 12 divisors (see below), whose sum is σ = 250450368. Its totient is φ = 67084800.

The previous prime is 138642043. The next prime is 138642047. The reversal of 138642044 is 440246831.

It is a self number, because there is not a number n which added to its sum of digits gives 138642044.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138642041) 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 3 ways as a sum of consecutive naturals, for example, 558917 + ... + 559164.

It is an arithmetic number, because the mean of its divisors is an integer number (20870864).

Almost surely, 2^138642044 is an apocalyptic number.

It is an amenable number.

138642044 is a deficient number, since it is larger than the sum of its proper divisors (111808324).

138642044 is a wasteful number, since it uses less digits than its factorization.

138642044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118116 (or 1118114 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 138642044 is about 11774.6356206891. The cubic root of 138642044 is about 517.5651006030.

Adding to 138642044 its reverse (440246831), we get a palindrome (578888875).

The spelling of 138642044 in words is "one hundred thirty-eight million, six hundred forty-two thousand, forty-four".