16661237 has 2 divisors, whose sum is σ = 16661238. Its totient is φ = 16661236.

The previous prime is 16661221. The next prime is 16661243. The reversal of 16661237 is 73216661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16532356 + 128881 = 4066^2 + 359^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661237 - 2⁴ = 16661221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16661287) 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 as a sum of consecutive naturals, namely, 8330618 + 8330619.

It is an arithmetic number, because the mean of its divisors is an integer number (8330619).

Almost surely, 2^16661237 is an apocalyptic number.

It is an amenable number.

16661237 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661237 is an equidigital number, since it uses as much as digits as its factorization.

16661237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 32.

The square root of 16661237 is about 4081.8178548289. The cubic root of 16661237 is about 255.4087357532.

Adding to 16661237 its reverse (73216661), we get a palindrome (89877898).

The spelling of 16661237 in words is "sixteen million, six hundred sixty-one thousand, two hundred thirty-seven".