136568639 has 4 divisors (see below), whose sum is σ = 136607856. Its totient is φ = 136529424.

The previous prime is 136568617. The next prime is 136568669. The reversal of 136568639 is 936865631.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-136568639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 136568593 and 136568602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136568669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13814 + ... + 21539.

It is an arithmetic number, because the mean of its divisors is an integer number (34151964).

Almost surely, 2^136568639 is an apocalyptic number.

136568639 is a deficient number, since it is larger than the sum of its proper divisors (39217).

136568639 is an equidigital number, since it uses as much as digits as its factorization.

136568639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39216.

The product of its digits is 699840, while the sum is 47.

The square root of 136568639 is about 11686.2585543877. The cubic root of 136568639 is about 514.9720523999.

The spelling of 136568639 in words is "one hundred thirty-six million, five hundred sixty-eight thousand, six hundred thirty-nine".