166275409 has 2 divisors, whose sum is σ = 166275410. Its totient is φ = 166275408.

The previous prime is 166275401. The next prime is 166275437. The reversal of 166275409 is 904572661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108743184 + 57532225 = 10428^2 + 7585^2 .

It is an emirp because it is prime and its reverse (904572661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166275409 - 2³ = 166275401 is a prime.

It is not a weakly prime, because it can be changed into another prime (166275401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83137704 + 83137705.

It is an arithmetic number, because the mean of its divisors is an integer number (83137705).

Almost surely, 2^166275409 is an apocalyptic number.

It is an amenable number.

166275409 is a deficient number, since it is larger than the sum of its proper divisors (1).

166275409 is an equidigital number, since it uses as much as digits as its factorization.

166275409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 166275409 is about 12894.7822393401. The cubic root of 166275409 is about 549.8902359470.

The spelling of 166275409 in words is "one hundred sixty-six million, two hundred seventy-five thousand, four hundred nine".