13721729 has 4 divisors (see below), whose sum is σ = 15681984. Its totient is φ = 11761476.

The previous prime is 13721723. The next prime is 13721761. The reversal of 13721729 is 92712731.

13721729 is digitally balanced in base 3, 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 a cyclic number.

It is not a de Polignac number, because 13721729 - 2⁴ = 13721713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13721695 and 13721704.

It is not an unprimeable number, because it can be changed into a prime (13721723) 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, 980117 + ... + 980130.

It is an arithmetic number, because the mean of its divisors is an integer number (3920496).

Almost surely, 2^13721729 is an apocalyptic number.

It is an amenable number.

13721729 is a deficient number, since it is larger than the sum of its proper divisors (1960255).

13721729 is an equidigital number, since it uses as much as digits as its factorization.

13721729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1960254.

The product of its digits is 5292, while the sum is 32.

The square root of 13721729 is about 3704.2852211999. The cubic root of 13721729 is about 239.4066883994.

The spelling of 13721729 in words is "thirteen million, seven hundred twenty-one thousand, seven hundred twenty-nine".