13730721 has 8 divisors (see below), whose sum is σ = 18697344. Its totient is φ = 8958960.

The previous prime is 13730719. The next prime is 13730729. The reversal of 13730721 is 12703731.

13730721 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 not a de Polignac number, because 13730721 - 2¹ = 13730719 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13730691 and 13730700.

It is not an unprimeable number, because it can be changed into a prime (13730729) 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, 48550 + ... + 48831.

It is an arithmetic number, because the mean of its divisors is an integer number (2337168).

Almost surely, 2^13730721 is an apocalyptic number.

It is an amenable number.

13730721 is a deficient number, since it is larger than the sum of its proper divisors (4966623).

13730721 is an equidigital number, since it uses as much as digits as its factorization.

13730721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97431.

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 13730721 is about 3705.4987518551. The cubic root of 13730721 is about 239.4589722595.

The spelling of 13730721 in words is "thirteen million, seven hundred thirty thousand, seven hundred twenty-one".