9711721 has 4 divisors (see below), whose sum is σ = 9727744. Its totient is φ = 9695700.

The previous prime is 9711659. The next prime is 9711733. The reversal of 9711721 is 1271179.

9711721 = T₂₅₄₃ + T₂₅₄₄ + T₂₅₄₅.

9711721 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 9711721 - 2¹¹ = 9709673 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 9711721.

It is not an unprimeable number, because it can be changed into a prime (9711521) 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, 7065 + ... + 8326.

It is an arithmetic number, because the mean of its divisors is an integer number (2431936).

Almost surely, 2^9711721 is an apocalyptic number.

9711721 is the 2545-th centered triangular number.

It is an amenable number.

9711721 is a deficient number, since it is larger than the sum of its proper divisors (16023).

9711721 is a wasteful number, since it uses less digits than its factorization.

9711721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16022.

The product of its digits is 882, while the sum is 28.

The square root of 9711721 is about 3116.3634255330. The cubic root of 9711721 is about 213.3529894541.

The spelling of 9711721 in words is "nine million, seven hundred eleven thousand, seven hundred twenty-one".