13138729 has 4 divisors (see below), whose sum is σ = 13354180. Its totient is φ = 12923280.

The previous prime is 13138721. The next prime is 13138757. The reversal of 13138729 is 92783131.

13138729 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5631129 + 7507600 = 2373^2 + 2740^2 .

It is a cyclic number.

It is not a de Polignac number, because 13138729 - 2³ = 13138721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13138694 and 13138703.

It is not an unprimeable number, because it can be changed into a prime (13138721) 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, 107634 + ... + 107755.

It is an arithmetic number, because the mean of its divisors is an integer number (3338545).

Almost surely, 2^13138729 is an apocalyptic number.

It is an amenable number.

13138729 is a deficient number, since it is larger than the sum of its proper divisors (215451).

13138729 is an equidigital number, since it uses as much as digits as its factorization.

13138729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215450.

The product of its digits is 9072, while the sum is 34.

The square root of 13138729 is about 3624.7384733247. The cubic root of 13138729 is about 235.9669169847.

The spelling of 13138729 in words is "thirteen million, one hundred thirty-eight thousand, seven hundred twenty-nine".