16661223 has 12 divisors (see below), whose sum is σ = 25112880. Its totient is φ = 10624416.

The previous prime is 16661221. The next prime is 16661237. The reversal of 16661223 is 32216661.

It is not a de Polignac number, because 16661223 - 2¹ = 16661221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40038 + ... + 40451.

It is an arithmetic number, because the mean of its divisors is an integer number (2092740).

Almost surely, 2^16661223 is an apocalyptic number.

16661223 is a deficient number, since it is larger than the sum of its proper divisors (8451657).

16661223 is a wasteful number, since it uses less digits than its factorization.

16661223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80518 (or 80515 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 16661223 is about 4081.8161399064. The cubic root of 16661223 is about 255.4086642154.

Adding to 16661223 its reverse (32216661), we get a palindrome (48877884).

The spelling of 16661223 in words is "sixteen million, six hundred sixty-one thousand, two hundred twenty-three".