13732721 has 4 divisors (see below), whose sum is σ = 14175744. Its totient is φ = 13289700.

The previous prime is 13732717. The next prime is 13732727. The reversal of 13732721 is 12723731.

13732721 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 13732721 - 2² = 13732717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13732727) 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, 221465 + ... + 221526.

It is an arithmetic number, because the mean of its divisors is an integer number (3543936).

Almost surely, 2^13732721 is an apocalyptic number.

It is an amenable number.

13732721 is a deficient number, since it is larger than the sum of its proper divisors (443023).

13732721 is an equidigital number, since it uses as much as digits as its factorization.

13732721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443022.

The product of its digits is 1764, while the sum is 26.

The square root of 13732721 is about 3705.7686112330. The cubic root of 13732721 is about 239.4705981285.

The spelling of 13732721 in words is "thirteen million, seven hundred thirty-two thousand, seven hundred twenty-one".