9956721 has 8 divisors (see below), whose sum is σ = 13293504. Its totient is φ = 6628880.

The previous prime is 9956719. The next prime is 9956729. The reversal of 9956721 is 1276599.

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 9956721 - 2¹ = 9956719 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9956721.

It is not an unprimeable number, because it can be changed into a prime (9956729) 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, 1060 + ... + 4586.

It is an arithmetic number, because the mean of its divisors is an integer number (1661688).

Almost surely, 2^9956721 is an apocalyptic number.

It is an amenable number.

9956721 is a deficient number, since it is larger than the sum of its proper divisors (3336783).

9956721 is a wasteful number, since it uses less digits than its factorization.

9956721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4471.

The product of its digits is 34020, while the sum is 39.

The square root of 9956721 is about 3155.4272293938. The cubic root of 9956721 is about 215.1322136132.

The spelling of 9956721 in words is "nine million, nine hundred fifty-six thousand, seven hundred twenty-one".