8566421 has 4 divisors (see below), whose sum is σ = 8573292. Its totient is φ = 8559552.

The previous prime is 8566409. The next prime is 8566427. The reversal of 8566421 is 1246658.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4202500 + 4363921 = 2050^2 + 2089^2 .

It is a cyclic number.

It is not a de Polignac number, because 8566421 - 2⁶ = 8566357 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 (8566427) 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 3 ways as a sum of consecutive naturals, for example, 980 + ... + 4253.

It is an arithmetic number, because the mean of its divisors is an integer number (2143323).

Almost surely, 2^8566421 is an apocalyptic number.

It is an amenable number.

8566421 is a deficient number, since it is larger than the sum of its proper divisors (6871).

8566421 is a wasteful number, since it uses less digits than its factorization.

8566421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870.

The product of its digits is 11520, while the sum is 32.

The square root of 8566421 is about 2926.8448882713. The cubic root of 8566421 is about 204.6129599921.

The spelling of 8566421 in words is "eight million, five hundred sixty-six thousand, four hundred twenty-one".