166405505 has 8 divisors (see below), whose sum is σ = 228213312. Its totient is φ = 114106608.

The previous prime is 166405493. The next prime is 166405549. The reversal of 166405505 is 505504661.

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

It is not a de Polignac number, because 166405505 - 2¹⁰ = 166404481 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2377187 + ... + 2377256.

It is an arithmetic number, because the mean of its divisors is an integer number (28526664).

Almost surely, 2^166405505 is an apocalyptic number.

It is an amenable number.

166405505 is a deficient number, since it is larger than the sum of its proper divisors (61807807).

166405505 is an equidigital number, since it uses as much as digits as its factorization.

166405505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4754455.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 166405505 is about 12899.8257740173. The cubic root of 166405505 is about 550.0336122709.

The spelling of 166405505 in words is "one hundred sixty-six million, four hundred five thousand, five hundred five".