138145985 has 8 divisors (see below), whose sum is σ = 165839400. Its totient is φ = 110473984.

The previous prime is 138145939. The next prime is 138146011. The reversal of 138145985 is 589541831.

It can be written as a sum of positive squares in 4 ways, for example, as 36481 + 138109504 = 191^2 + 11752^2 .

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 138145985 - 2¹² = 138141889 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18569 + ... + 24921.

It is an arithmetic number, because the mean of its divisors is an integer number (20729925).

Almost surely, 2^138145985 is an apocalyptic number.

It is an amenable number.

138145985 is a deficient number, since it is larger than the sum of its proper divisors (27693415).

138145985 is an equidigital number, since it uses as much as digits as its factorization.

138145985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10707.

The product of its digits is 172800, while the sum is 44.

The square root of 138145985 is about 11753.5520163055. The cubic root of 138145985 is about 516.9470830662.

The spelling of 138145985 in words is "one hundred thirty-eight million, one hundred forty-five thousand, nine hundred eighty-five".