166406805 has 30 divisors (see below), whose sum is σ = 298765698. Its totient is φ = 88611840.

The previous prime is 166406789. The next prime is 166406833. The reversal of 166406805 is 508604661.

166406805 is a `hidden beast` number, since 1 + 6 + 640 + 6 + 8 + 0 + 5 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 83942244 + 82464561 = 9162^2 + 9081^2 .

It is not a de Polignac number, because 166406805 - 2⁴ = 166406789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166406805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 259285 + ... + 259925.

Almost surely, 2^166406805 is an apocalyptic number.

166406805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166406805 is a deficient number, since it is larger than the sum of its proper divisors (132358893).

166406805 is an frugal number, since it uses more digits than its factorization.

166406805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299 (or 649 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 166406805 is about 12899.8761621963. The cubic root of 166406805 is about 550.0350445990.

The spelling of 166406805 in words is "one hundred sixty-six million, four hundred six thousand, eight hundred five".