166261643566 has 8 divisors (see below), whose sum is σ = 254698688160. Its totient is φ = 81362080848.

The previous prime is 166261643557. The next prime is 166261643573. The reversal of 166261643566 is 665346162661.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884370351 + ... + 884370538.

It is an arithmetic number, because the mean of its divisors is an integer number (31837336020).

Almost surely, 2^166261643566 is an apocalyptic number.

166261643566 is a deficient number, since it is larger than the sum of its proper divisors (88437044594).

166261643566 is a wasteful number, since it uses less digits than its factorization.

166261643566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768740938.

The product of its digits is 5598720, while the sum is 52.

The spelling of 166261643566 in words is "one hundred sixty-six billion, two hundred sixty-one million, six hundred forty-three thousand, five hundred sixty-six".