8666021 has 8 divisors (see below), whose sum is σ = 10665984. Its totient is φ = 6856560.

The previous prime is 8666017. The next prime is 8666023. The reversal of 8666021 is 1206668.

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 8666021 - 2² = 8666017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8666023) 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, 47525 + ... + 47706.

It is an arithmetic number, because the mean of its divisors is an integer number (1333248).

Almost surely, 2^8666021 is an apocalyptic number.

It is an amenable number.

8666021 is a deficient number, since it is larger than the sum of its proper divisors (1999963).

8666021 is a wasteful number, since it uses less digits than its factorization.

8666021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95251.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 8666021 is about 2943.8106257027. The cubic root of 8666021 is about 205.4029038328.

The spelling of 8666021 in words is "eight million, six hundred sixty-six thousand, twenty-one".