166661599 has 8 divisors (see below), whose sum is σ = 179751152. Its totient is φ = 153610560.

The previous prime is 166661581. The next prime is 166661609. The reversal of 166661599 is 995166661.

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

It is a cyclic number.

It is not a de Polignac number, because 166661599 - 2²³ = 158272991 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 (166661399) 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, 294 + ... + 18259.

It is an arithmetic number, because the mean of its divisors is an integer number (22468894).

Almost surely, 2^166661599 is an apocalyptic number.

166661599 is a deficient number, since it is larger than the sum of its proper divisors (13089553).

166661599 is a wasteful number, since it uses less digits than its factorization.

166661599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19257.

The product of its digits is 524880, while the sum is 49.

The square root of 166661599 is about 12909.7482159800. The cubic root of 166661599 is about 550.3156304037.

The spelling of 166661599 in words is "one hundred sixty-six million, six hundred sixty-one thousand, five hundred ninety-nine".