166691959 has 8 divisors (see below), whose sum is σ = 200531840. Its totient is φ = 135358776.

The previous prime is 166691897. The next prime is 166691981. The reversal of 166691959 is 959196661.

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

It is not a de Polignac number, because 166691959 - 2¹¹ = 166689911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166691989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 626529 + ... + 626794.

It is an arithmetic number, because the mean of its divisors is an integer number (25066480).

Almost surely, 2^166691959 is an apocalyptic number.

166691959 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

166691959 is a deficient number, since it is larger than the sum of its proper divisors (33839881).

166691959 is a wasteful number, since it uses less digits than its factorization.

166691959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253349.

The product of its digits is 787320, while the sum is 52.

The square root of 166691959 is about 12910.9240180554. The cubic root of 166691959 is about 550.3490445559.

The spelling of 166691959 in words is "one hundred sixty-six million, six hundred ninety-one thousand, nine hundred fifty-nine".