166585661 has 24 divisors (see below), whose sum is σ = 191520000. Its totient is φ = 144619200.

The previous prime is 166585649. The next prime is 166585691.

166585661 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 166585661 - 2¹⁸ = 166323517 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 (166585621) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 333590 + ... + 334088.

It is an arithmetic number, because the mean of its divisors is an integer number (7980000).

Almost surely, 2^166585661 is an apocalyptic number.

166585661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166585661 is a deficient number, since it is larger than the sum of its proper divisors (24934339).

166585661 is a wasteful number, since it uses less digits than its factorization.

166585661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 630 counting only the distinct ones).

The product of its digits is 259200, while the sum is 44.

The square root of 166585661 is about 12906.8067700729. The cubic root of 166585661 is about 550.2320354279.

The spelling of 166585661 in words is "one hundred sixty-six million, five hundred eighty-five thousand, six hundred sixty-one".