136639 has 4 divisors (see below), whose sum is σ = 138024. Its totient is φ = 135256.

The previous prime is 136621. The next prime is 136649. The reversal of 136639 is 936631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936631 = 359 ⋅2609.

It is a cyclic number.

It is not a de Polignac number, because 136639 - 2⁵ = 136607 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 (136649) 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 3 ways as a sum of consecutive naturals, for example, 532 + ... + 745.

It is an arithmetic number, because the mean of its divisors is an integer number (34506).

2¹³⁶⁶³⁹ is an apocalyptic number.

136639 is a deficient number, since it is larger than the sum of its proper divisors (1385).

136639 is a wasteful number, since it uses less digits than its factorization.

136639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1384.

The product of its digits is 2916, while the sum is 28.

The square root of 136639 is about 369.6471290298. The cubic root of 136639 is about 51.5060476136.

The spelling of 136639 in words is "one hundred thirty-six thousand, six hundred thirty-nine".