166672221 has 8 divisors (see below), whose sum is σ = 223458144. Its totient is φ = 110500560.

The previous prime is 166672211. The next prime is 166672223. The reversal of 166672221 is 122276661.

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

It is not a de Polignac number, because 166672221 - 2⁵ = 166672189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166672223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152931 + ... + 154016.

It is an arithmetic number, because the mean of its divisors is an integer number (27932268).

Almost surely, 2^166672221 is an apocalyptic number.

It is an amenable number.

166672221 is a deficient number, since it is larger than the sum of its proper divisors (56785923).

166672221 is a wasteful number, since it uses less digits than its factorization.

166672221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307131.

The product of its digits is 12096, while the sum is 33.

The square root of 166672221 is about 12910.1596039708. The cubic root of 166672221 is about 550.3273214161.

The spelling of 166672221 in words is "one hundred sixty-six million, six hundred seventy-two thousand, two hundred twenty-one".