9721864 has 16 divisors (see below), whose sum is σ = 18266220. Its totient is φ = 4850880.

The previous prime is 9721853. The next prime is 9721867. The reversal of 9721864 is 4681279.

It can be written as a sum of positive squares in 2 ways, for example, as 7344100 + 2377764 = 2710^2 + 1542^2 .

It is not an unprimeable number, because it can be changed into a prime (9721867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4294 + ... + 6154.

Almost surely, 2^9721864 is an apocalyptic number.

It is an amenable number.

9721864 is a deficient number, since it is larger than the sum of its proper divisors (8544356).

9721864 is a wasteful number, since it uses less digits than its factorization.

9721864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2520 (or 2516 counting only the distinct ones).

The product of its digits is 24192, while the sum is 37.

The square root of 9721864 is about 3117.9903784329. The cubic root of 9721864 is about 213.4272394738.

It can be divided in two parts, 9721 and 864, that added together give a triangular number (10585 = T₁₄₅).

The spelling of 9721864 in words is "nine million, seven hundred twenty-one thousand, eight hundred sixty-four".