166163661 has 36 divisors (see below), whose sum is σ = 265791708. Its totient is φ = 99677952.

The previous prime is 166163651. The next prime is 166163677. The reversal of 166163661 is 166361661.

It is a happy number.

166163661 is a `hidden beast` number, since 1 + 6 + 616 + 36 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 108555561 + 57608100 = 10419^2 + 7590^2 .

It is not a de Polignac number, because 166163661 - 2⁵ = 166163629 is a prime.

It is a super-2 number, since 2×166163661² = 55220724473845842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166163651) 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 35 ways as a sum of consecutive naturals, for example, 79911 + ... + 81963.

It is an arithmetic number, because the mean of its divisors is an integer number (7383103).

Almost surely, 2^166163661 is an apocalyptic number.

It is an amenable number.

166163661 is a deficient number, since it is larger than the sum of its proper divisors (99628047).

166163661 is a wasteful number, since it uses less digits than its factorization.

166163661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2122 (or 2096 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 166163661 is about 12890.4484406090. The cubic root of 166163661 is about 549.7670208836.

The spelling of 166163661 in words is "one hundred sixty-six million, one hundred sixty-three thousand, six hundred sixty-one".