166446661 has 4 divisors (see below), whose sum is σ = 168062752. Its totient is φ = 164830572.

The previous prime is 166446641. The next prime is 166446667. The reversal of 166446661 is 166644661.

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: 166644661 = 83 ⋅2007767.

It is a cyclic number.

It is not a de Polignac number, because 166446661 - 2⁵ = 166446629 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 (166446667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807891 + ... + 808096.

It is an arithmetic number, because the mean of its divisors is an integer number (42015688).

Almost surely, 2^166446661 is an apocalyptic number.

It is an amenable number.

166446661 is a deficient number, since it is larger than the sum of its proper divisors (1616091).

166446661 is a wasteful number, since it uses less digits than its factorization.

166446661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1616090.

The product of its digits is 124416, while the sum is 40.

The square root of 166446661 is about 12901.4208907391. The cubic root of 166446661 is about 550.0789539547.

The spelling of 166446661 in words is "one hundred sixty-six million, four hundred forty-six thousand, six hundred sixty-one".