166606661 has 8 divisors (see below), whose sum is σ = 180176640. Its totient is φ = 153144432.

The previous prime is 166606637. The next prime is 166606703.

166606661 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166606661 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 (166606621) 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, 23705 + ... + 29918.

It is an arithmetic number, because the mean of its divisors is an integer number (22522080).

Almost surely, 2^166606661 is an apocalyptic number.

It is an amenable number.

166606661 is a deficient number, since it is larger than the sum of its proper divisors (13569979).

166606661 is a wasteful number, since it uses less digits than its factorization.

166606661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53875.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 166606661 is about 12907.6202686630. The cubic root of 166606661 is about 550.2551554394.

The spelling of 166606661 in words is "one hundred sixty-six million, six hundred six thousand, six hundred sixty-one".