16661243 has 2 divisors, whose sum is σ = 16661244. Its totient is φ = 16661242.

The previous prime is 16661237. The next prime is 16661251. The reversal of 16661243 is 34216661.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (34216661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16661243 - 2¹⁰ = 16660219 is a prime.

It is not a weakly prime, because it can be changed into another prime (16661213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330621 + 8330622.

It is an arithmetic number, because the mean of its divisors is an integer number (8330622).

Almost surely, 2^16661243 is an apocalyptic number.

16661243 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661243 is an equidigital number, since it uses as much as digits as its factorization.

16661243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 29.

The square root of 16661243 is about 4081.8185897955. The cubic root of 16661243 is about 255.4087664122.

The spelling of 16661243 in words is "sixteen million, six hundred sixty-one thousand, two hundred forty-three".