13158721 has 8 divisors (see below), whose sum is σ = 13665600. Its totient is φ = 12655440.

The previous prime is 13158709. The next prime is 13158749. The reversal of 13158721 is 12785131.

13158721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13158721 - 2¹¹ = 13156673 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13158721.

It is not an unprimeable number, because it can be changed into a prime (13158701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8290 + ... + 9748.

It is an arithmetic number, because the mean of its divisors is an integer number (1708200).

Almost surely, 2^13158721 is an apocalyptic number.

It is an amenable number.

13158721 is a deficient number, since it is larger than the sum of its proper divisors (506879).

13158721 is a wasteful number, since it uses less digits than its factorization.

13158721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1799.

The product of its digits is 1680, while the sum is 28.

The square root of 13158721 is about 3627.4951412786. The cubic root of 13158721 is about 236.0865394109.

The spelling of 13158721 in words is "thirteen million, one hundred fifty-eight thousand, seven hundred twenty-one".