135568639 has 4 divisors (see below), whose sum is σ = 135592024. Its totient is φ = 135545256.

The previous prime is 135568619. The next prime is 135568681. The reversal of 135568639 is 936865531.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 135568639 - 2²⁵ = 102014207 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 (135568619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4249 + ... + 17005.

It is an arithmetic number, because the mean of its divisors is an integer number (33898006).

Almost surely, 2^135568639 is an apocalyptic number.

135568639 is a deficient number, since it is larger than the sum of its proper divisors (23385).

135568639 is a wasteful number, since it uses less digits than its factorization.

135568639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23384.

The product of its digits is 583200, while the sum is 46.

The square root of 135568639 is about 11643.3946510457. The cubic root of 135568639 is about 513.7120410108.

The spelling of 135568639 in words is "one hundred thirty-five million, five hundred sixty-eight thousand, six hundred thirty-nine".