9943643021 has 8 divisors (see below), whose sum is σ = 10844090880. Its totient is φ = 9062559792.

The previous prime is 9943642999. The next prime is 9943643023. The reversal of 9943643021 is 1203463499.

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

It is not a de Polignac number, because 9943643021 - 2¹⁸ = 9943380877 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9943643021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9943643023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4840085 + ... + 4842138.

It is an arithmetic number, because the mean of its divisors is an integer number (1355511360).

Almost surely, 2^9943643021 is an apocalyptic number.

It is an amenable number.

9943643021 is a deficient number, since it is larger than the sum of its proper divisors (900447859).

9943643021 is a wasteful number, since it uses less digits than its factorization.

9943643021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9682315.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 9943643021 is about 99717.8169686842. The cubic root of 9943643021 is about 2150.3798154296.

The spelling of 9943643021 in words is "nine billion, nine hundred forty-three million, six hundred forty-three thousand, twenty-one".