166506321 has 8 divisors (see below), whose sum is σ = 222105664. Its totient is φ = 110955600.

The previous prime is 166506317. The next prime is 166506331. The reversal of 166506321 is 123605661.

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

It is not a de Polignac number, because 166506321 - 2² = 166506317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166506331) 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, 3226 + ... + 18531.

It is an arithmetic number, because the mean of its divisors is an integer number (27763208).

Almost surely, 2^166506321 is an apocalyptic number.

It is an amenable number.

166506321 is a deficient number, since it is larger than the sum of its proper divisors (55599343).

166506321 is a wasteful number, since it uses less digits than its factorization.

166506321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24311.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 166506321 is about 12903.7328320142. The cubic root of 166506321 is about 550.1446682802.

The spelling of 166506321 in words is "one hundred sixty-six million, five hundred six thousand, three hundred twenty-one".