9821621 has 8 divisors (see below), whose sum is σ = 10342080. Its totient is φ = 9308992.

The previous prime is 9821599. The next prime is 9821629. The reversal of 9821621 is 1261289.

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 9821621 - 2¹⁸ = 9559477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9821629) 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, 710 + ... + 4488.

It is an arithmetic number, because the mean of its divisors is an integer number (1292760).

Almost surely, 2^9821621 is an apocalyptic number.

It is an amenable number.

9821621 is a deficient number, since it is larger than the sum of its proper divisors (520459).

9821621 is a wasteful number, since it uses less digits than its factorization.

9821621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3915.

The product of its digits is 1728, while the sum is 29.

The square root of 9821621 is about 3133.9465534690. The cubic root of 9821621 is about 214.1547560250.

The spelling of 9821621 in words is "nine million, eight hundred twenty-one thousand, six hundred twenty-one".