138536 has 8 divisors (see below), whose sum is σ = 259770. Its totient is φ = 69264.

The previous prime is 138517. The next prime is 138547. The reversal of 138536 is 635831.

It can be written as a sum of positive squares in only one way, i.e., 96100 + 42436 = 310^2 + 206^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

138536 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8651 + ... + 8666.

2¹³⁸⁵³⁶ is an apocalyptic number.

It is an amenable number.

138536 is a deficient number, since it is larger than the sum of its proper divisors (121234).

138536 is a wasteful number, since it uses less digits than its factorization.

138536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17323 (or 17319 counting only the distinct ones).

The product of its digits is 2160, while the sum is 26.

The square root of 138536 is about 372.2042450053. The cubic root of 138536 is about 51.7433109202.

The spelling of 138536 in words is "one hundred thirty-eight thousand, five hundred thirty-six".