1566223 has 4 divisors (see below), whose sum is σ = 1568808. Its totient is φ = 1563640.

The previous prime is 1566217. The next prime is 1566239. The reversal of 1566223 is 3226651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1566223 - 2¹⁷ = 1435151 is a prime.

It is a Duffinian number.

1566223 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1566263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 165 + ... + 1777.

It is an arithmetic number, because the mean of its divisors is an integer number (392202).

2^1566223 is an apocalyptic number.

1566223 is a deficient number, since it is larger than the sum of its proper divisors (2585).

1566223 is an equidigital number, since it uses as much as digits as its factorization.

1566223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2584.

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

The square root of 1566223 is about 1251.4883139686. The cubic root of 1566223 is about 116.1318111251.

It can be divided in two parts, 15 and 66223, that multiplied together give a triangular number (993345 = T₁₄₀₉).

The spelling of 1566223 in words is "one million, five hundred sixty-six thousand, two hundred twenty-three".