138631555 has 8 divisors (see below), whose sum is σ = 166528800. Its totient is φ = 110791296.

The previous prime is 138631553. The next prime is 138631573. The reversal of 138631555 is 555136831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138631555 - 2¹ = 138631553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138631553) 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, 8695 + ... + 18784.

It is an arithmetic number, because the mean of its divisors is an integer number (20816100).

Almost surely, 2^138631555 is an apocalyptic number.

138631555 is a deficient number, since it is larger than the sum of its proper divisors (27897245).

138631555 is a wasteful number, since it uses less digits than its factorization.

138631555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28493.

The product of its digits is 54000, while the sum is 37.

The square root of 138631555 is about 11774.1902056999. The cubic root of 138631555 is about 517.5520480996.

The spelling of 138631555 in words is "one hundred thirty-eight million, six hundred thirty-one thousand, five hundred fifty-five".