16851649 has 2 divisors, whose sum is σ = 16851650. Its totient is φ = 16851648.

The previous prime is 16851647. The next prime is 16851683. The reversal of 16851649 is 94615861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10195249 + 6656400 = 3193^2 + 2580^2 .

It is a cyclic number.

It is not a de Polignac number, because 16851649 - 2¹ = 16851647 is a prime.

Together with 16851647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (16851647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8425824 + 8425825.

It is an arithmetic number, because the mean of its divisors is an integer number (8425825).

Almost surely, 2^16851649 is an apocalyptic number.

It is an amenable number.

16851649 is a deficient number, since it is larger than the sum of its proper divisors (1).

16851649 is an equidigital number, since it uses as much as digits as its factorization.

16851649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 40.

The square root of 16851649 is about 4105.0760041685. The cubic root of 16851649 is about 256.3780273194.

The spelling of 16851649 in words is "sixteen million, eight hundred fifty-one thousand, six hundred forty-nine".