166541 has 2 divisors, whose sum is σ = 166542. Its totient is φ = 166540.

The previous prime is 166487. The next prime is 166561. The reversal of 166541 is 145661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137641 + 28900 = 371^2 + 170^2 .

It is an emirp because it is prime and its reverse (145661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166541 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 166541.

It is not a weakly prime, because it can be changed into another prime (166561) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83270 + 83271.

It is an arithmetic number, because the mean of its divisors is an integer number (83271).

2¹⁶⁶⁵⁴¹ is an apocalyptic number.

It is an amenable number.

166541 is a deficient number, since it is larger than the sum of its proper divisors (1).

166541 is an equidigital number, since it uses as much as digits as its factorization.

166541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

The square root of 166541 is about 408.0943518355. The cubic root of 166541 is about 55.0182859308.

It can be divided in two parts, 1665 and 41, that multiplied together give a triangular number (68265 = T₃₆₉).

The spelling of 166541 in words is "one hundred sixty-six thousand, five hundred forty-one".