16649 has 2 divisors, whose sum is σ = 16650. Its totient is φ = 16648.

The previous prime is 16633. The next prime is 16651. The reversal of 16649 is 94661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15625 + 1024 = 125^2 + 32^2 .

It is a cyclic number.

It is not a de Polignac number, because 16649 - 2⁴ = 16633 is a prime.

Together with 16651, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 11 and base 15.

It is a nialpdrome in base 12.

It is not a weakly prime, because it can be changed into another prime (16619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8324 + 8325.

It is an arithmetic number, because the mean of its divisors is an integer number (8325).

2¹⁶⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

16649 is a deficient number, since it is larger than the sum of its proper divisors (1).

16649 is an equidigital number, since it uses as much as digits as its factorization.

16649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 16649 is about 129.0310040262. The cubic root of 16649 is about 25.5346191334.

The spelling of 16649 in words is "sixteen thousand, six hundred forty-nine".