16665841 has 2 divisors, whose sum is σ = 16665842. Its totient is φ = 16665840.

The previous prime is 16665839. The next prime is 16665851. The reversal of 16665841 is 14856661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14899600 + 1766241 = 3860^2 + 1329^2 .

It is a cyclic number.

It is not a de Polignac number, because 16665841 - 2¹ = 16665839 is a prime.

Together with 16665839, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 16665841.

It is not a weakly prime, because it can be changed into another prime (16665851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8332920 + 8332921.

It is an arithmetic number, because the mean of its divisors is an integer number (8332921).

Almost surely, 2^16665841 is an apocalyptic number.

It is an amenable number.

16665841 is a deficient number, since it is larger than the sum of its proper divisors (1).

16665841 is an equidigital number, since it uses as much as digits as its factorization.

16665841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 37.

The square root of 16665841 is about 4082.3817802846. The cubic root of 16665841 is about 255.4322592872.

The spelling of 16665841 in words is "sixteen million, six hundred sixty-five thousand, eight hundred forty-one".