9943821 has 12 divisors (see below), whose sum is σ = 15119520. Its totient is φ = 6280200.

The previous prime is 9943819. The next prime is 9943849. The reversal of 9943821 is 1283499.

It is not a de Polignac number, because 9943821 - 2¹ = 9943819 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9943721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28905 + ... + 29246.

It is an arithmetic number, because the mean of its divisors is an integer number (1259960).

Almost surely, 2^9943821 is an apocalyptic number.

It is an amenable number.

9943821 is a deficient number, since it is larger than the sum of its proper divisors (5175699).

9943821 is a wasteful number, since it uses less digits than its factorization.

9943821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58176 (or 58173 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 9943821 is about 3153.3824696665. The cubic root of 9943821 is about 215.0392645072.

The spelling of 9943821 in words is "nine million, nine hundred forty-three thousand, eight hundred twenty-one".