166805149 has 4 divisors (see below), whose sum is σ = 190634464. Its totient is φ = 142975836.

The previous prime is 166805147. The next prime is 166805153. The reversal of 166805149 is 941508661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 941508661 = 89 ⋅10578749.

It is a cyclic number.

It is not a de Polignac number, because 166805149 - 2¹ = 166805147 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166805147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11914647 + ... + 11914660.

It is an arithmetic number, because the mean of its divisors is an integer number (47658616).

Almost surely, 2^166805149 is an apocalyptic number.

It is an amenable number.

166805149 is a deficient number, since it is larger than the sum of its proper divisors (23829315).

166805149 is an equidigital number, since it uses as much as digits as its factorization.

166805149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23829314.

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

The square root of 166805149 is about 12915.3067714244. The cubic root of 166805149 is about 550.4735854837.

The spelling of 166805149 in words is "one hundred sixty-six million, eight hundred five thousand, one hundred forty-nine".