166125109 has 4 divisors (see below), whose sum is σ = 166408704. Its totient is φ = 165841516.

The previous prime is 166125107. The next prime is 166125121. The reversal of 166125109 is 901521661.

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: 901521661 = 18481 ⋅48781.

It is a cyclic number.

It is not a de Polignac number, because 166125109 - 2¹ = 166125107 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 (166125107) 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, 140917 + ... + 142090.

It is an arithmetic number, because the mean of its divisors is an integer number (41602176).

Almost surely, 2^166125109 is an apocalyptic number.

It is an amenable number.

166125109 is a deficient number, since it is larger than the sum of its proper divisors (283595).

166125109 is an equidigital number, since it uses as much as digits as its factorization.

166125109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283594.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 166125109 is about 12888.9529830782. The cubic root of 166125109 is about 549.7245000392.

The spelling of 166125109 in words is "one hundred sixty-six million, one hundred twenty-five thousand, one hundred nine".