866040221 has 8 divisors (see below), whose sum is σ = 876355200. Its totient is φ = 855738400.

The previous prime is 866040209. The next prime is 866040247. The reversal of 866040221 is 122040668.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866040221 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 (866040251) 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, 207170 + ... + 211308.

It is an arithmetic number, because the mean of its divisors is an integer number (109544400).

Almost surely, 2^866040221 is an apocalyptic number.

It is an amenable number.

866040221 is a deficient number, since it is larger than the sum of its proper divisors (10314979).

866040221 is a wasteful number, since it uses less digits than its factorization.

866040221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6579.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 866040221 is about 29428.5613137985. The cubic root of 866040221 is about 953.1897291179.

Adding to 866040221 its reverse (122040668), we get a palindrome (988080889).

The spelling of 866040221 in words is "eight hundred sixty-six million, forty thousand, two hundred twenty-one".