9866021 has 8 divisors (see below), whose sum is σ = 10793088. Its totient is φ = 8944000.

The previous prime is 9866009. The next prime is 9866033. The reversal of 9866021 is 1206689.

It is an interprime number because it is at equal distance from previous prime (9866009) and next prime (9866033).

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 9866021 - 2¹⁸ = 9603877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9866041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3701 + ... + 5781.

It is an arithmetic number, because the mean of its divisors is an integer number (1349136).

Almost surely, 2^9866021 is an apocalyptic number.

It is an amenable number.

9866021 is a deficient number, since it is larger than the sum of its proper divisors (927067).

9866021 is a wasteful number, since it uses less digits than its factorization.

9866021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2523.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 9866021 is about 3141.0222858172. The cubic root of 9866021 is about 214.4769763904.

It can be divided in two parts, 986 and 6021, that added together give a palindrome (7007).

The spelling of 9866021 in words is "nine million, eight hundred sixty-six thousand, twenty-one".