166804221 has 8 divisors (see below), whose sum is σ = 235488384. Its totient is φ = 104661440.

The previous prime is 166804217. The next prime is 166804229. The reversal of 166804221 is 122408661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166804221 - 2² = 166804217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166804229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1635285 + ... + 1635386.

It is an arithmetic number, because the mean of its divisors is an integer number (29436048).

Almost surely, 2^166804221 is an apocalyptic number.

It is an amenable number.

166804221 is a deficient number, since it is larger than the sum of its proper divisors (68684163).

166804221 is a wasteful number, since it uses less digits than its factorization.

166804221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3270691.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 166804221 is about 12915.2708450113. The cubic root of 166804221 is about 550.4725646511.

The spelling of 166804221 in words is "one hundred sixty-six million, eight hundred four thousand, two hundred twenty-one".