9921680 has 20 divisors (see below), whose sum is σ = 23068092. Its totient is φ = 3968640.

The previous prime is 9921679. The next prime is 9921731. The reversal of 9921680 is 861299.

It can be written as a sum of positive squares in 2 ways, for example, as 6990736 + 2930944 = 2644^2 + 1712^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 9921680.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61931 + ... + 62090.

Almost surely, 2^9921680 is an apocalyptic number.

It is an amenable number.

9921680 is an abundant number, since it is smaller than the sum of its proper divisors (13146412).

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

9921680 is a wasteful number, since it uses less digits than its factorization.

9921680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124034 (or 124028 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 9921680 is about 3149.8698385806. The cubic root of 9921680 is about 214.8795431252.

It can be divided in two parts, 9921 and 680, that added together give a palindrome (10601).

The spelling of 9921680 in words is "nine million, nine hundred twenty-one thousand, six hundred eighty".