3566221 has 4 divisors (see below), whose sum is σ = 3653244. Its totient is φ = 3479200.

The previous prime is 3566197. The next prime is 3566231. The reversal of 3566221 is 1226653.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1226653 = 47 ⋅26099.

It can be written as a sum of positive squares in 2 ways, for example, as 275625 + 3290596 = 525^2 + 1814^2 .

It is a cyclic number.

It is not a de Polignac number, because 3566221 - 2¹³ = 3558029 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 (3566231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43450 + ... + 43531.

It is an arithmetic number, because the mean of its divisors is an integer number (913311).

Almost surely, 2^3566221 is an apocalyptic number.

It is an amenable number.

3566221 is a deficient number, since it is larger than the sum of its proper divisors (87023).

3566221 is an equidigital number, since it uses as much as digits as its factorization.

3566221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87022.

The product of its digits is 2160, while the sum is 25.

The square root of 3566221 is about 1888.4440685390. Note that the first 3 decimals coincide. The cubic root of 3566221 is about 152.7810244110.

The spelling of 3566221 in words is "three million, five hundred sixty-six thousand, two hundred twenty-one".