9721680 has 40 divisors (see below), whose sum is σ = 30137952. Its totient is φ = 2592384.

The previous prime is 9721667. The next prime is 9721687. The reversal of 9721680 is 861279.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×9721680² = 189022124044800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9721687) 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, 20014 + ... + 20493.

Almost surely, 2^9721680 is an apocalyptic number.

It is an amenable number.

9721680 is an abundant number, since it is smaller than the sum of its proper divisors (20416272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9721680 is a wasteful number, since it uses less digits than its factorization.

9721680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40523 (or 40517 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 9721680 is about 3117.9608721086. The cubic root of 9721680 is about 213.4258929947.

It can be divided in two parts, 9721 and 680, that added together give a palindrome (10401).

The spelling of 9721680 in words is "nine million, seven hundred twenty-one thousand, six hundred eighty".