138642559 has 4 divisors (see below), whose sum is σ = 151246440. Its totient is φ = 126038680.

The previous prime is 138642557. The next prime is 138642583. The reversal of 138642559 is 955246831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138642559 - 2¹ = 138642557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138642557) 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, 6301924 + ... + 6301945.

It is an arithmetic number, because the mean of its divisors is an integer number (37811610).

Almost surely, 2^138642559 is an apocalyptic number.

138642559 is a deficient number, since it is larger than the sum of its proper divisors (12603881).

138642559 is a wasteful number, since it uses less digits than its factorization.

138642559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12603880.

The product of its digits is 259200, while the sum is 43.

The square root of 138642559 is about 11774.6574897107. The cubic root of 138642559 is about 517.5657414516.

The spelling of 138642559 in words is "one hundred thirty-eight million, six hundred forty-two thousand, five hundred fifty-nine".