13607721 has 12 divisors (see below), whose sum is σ = 19689072. Its totient is φ = 9056376.

The previous prime is 13607707. The next prime is 13607731. The reversal of 13607721 is 12770631.

13607721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13607721 - 2⁵ = 13607689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13607731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7330 + ... + 8996.

It is an arithmetic number, because the mean of its divisors is an integer number (1640756).

Almost surely, 2^13607721 is an apocalyptic number.

It is an amenable number.

13607721 is a deficient number, since it is larger than the sum of its proper divisors (6081351).

13607721 is a wasteful number, since it uses less digits than its factorization.

13607721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2580 (or 2577 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 13607721 is about 3688.8644594238. The cubic root of 13607721 is about 238.7418008386.

The spelling of 13607721 in words is "thirteen million, six hundred seven thousand, seven hundred twenty-one".