16657 has 2 divisors, whose sum is σ = 16658. Its totient is φ = 16656.

The previous prime is 16651. The next prime is 16661. The reversal of 16657 is 75661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16641 + 16 = 129^2 + 4^2 .

It is a cyclic number.

It is not a de Polignac number, because 16657 - 2³ = 16649 is a prime.

16657 is a lucky number.

It is a nialpdrome in base 13 and base 16.

It is not a weakly prime, because it can be changed into another prime (16651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8328 + 8329.

It is an arithmetic number, because the mean of its divisors is an integer number (8329).

2¹⁶⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

16657 is a deficient number, since it is larger than the sum of its proper divisors (1).

16657 is an equidigital number, since it uses as much as digits as its factorization.

16657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 25.

The square root of 16657 is about 129.0620006044. The cubic root of 16657 is about 25.5387083528.

The spelling of 16657 in words is "sixteen thousand, six hundred fifty-seven".