138565538 has 16 divisors (see below), whose sum is σ = 227665080. Its totient is φ = 62958336.

The previous prime is 138565529. The next prime is 138565543. The reversal of 138565538 is 835565831.

It can be written as a sum of positive squares in 4 ways, for example, as 99540529 + 39025009 = 9977^2 + 6247^2 .

It is a Curzon number.

It is an unprimeable number.

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, 69281 + ... + 71252.

Almost surely, 2^138565538 is an apocalyptic number.

138565538 is a deficient number, since it is larger than the sum of its proper divisors (89099542).

138565538 is a wasteful number, since it uses less digits than its factorization.

138565538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140581.

The product of its digits is 432000, while the sum is 44.

The square root of 138565538 is about 11771.3864094252. The cubic root of 138565538 is about 517.4698814805.

The spelling of 138565538 in words is "one hundred thirty-eight million, five hundred sixty-five thousand, five hundred thirty-eight".