9719721 has 12 divisors (see below), whose sum is σ = 15316080. Its totient is φ = 5890680.

The previous prime is 9719707. The next prime is 9719729. The reversal of 9719721 is 1279179.

9719721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9719721 - 2⁶ = 9719657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9719729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48991 + ... + 49188.

It is an arithmetic number, because the mean of its divisors is an integer number (1276340).

Almost surely, 2^9719721 is an apocalyptic number.

It is an amenable number.

9719721 is a deficient number, since it is larger than the sum of its proper divisors (5596359).

9719721 is a wasteful number, since it uses less digits than its factorization.

9719721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98196 (or 98193 counting only the distinct ones).

The product of its digits is 7938, while the sum is 36.

The square root of 9719721 is about 3117.6467086570. The cubic root of 9719721 is about 213.4115563296.

It can be divided in two parts, 9719 and 721, that added together give a triangular number (10440 = T₁₄₄).

The spelling of 9719721 in words is "nine million, seven hundred nineteen thousand, seven hundred twenty-one".