9856721 has 8 divisors (see below), whose sum is σ = 11310720. Its totient is φ = 8414208.

The previous prime is 9856709. The next prime is 9856727. The reversal of 9856721 is 1276589.

9856721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9856721 - 2¹⁰ = 9855697 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9856727) 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, 941 + ... + 4538.

It is an arithmetic number, because the mean of its divisors is an integer number (1413840).

Almost surely, 2^9856721 is an apocalyptic number.

It is an amenable number.

9856721 is a deficient number, since it is larger than the sum of its proper divisors (1453999).

9856721 is a wasteful number, since it uses less digits than its factorization.

9856721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5743.

The product of its digits is 30240, while the sum is 38.

The square root of 9856721 is about 3139.5415270386. The cubic root of 9856721 is about 214.4095644472.

The spelling of 9856721 in words is "nine million, eight hundred fifty-six thousand, seven hundred twenty-one".