166706605778 has 8 divisors (see below), whose sum is σ = 250089784572. Its totient is φ = 83343344256.

The previous prime is 166706605757. The next prime is 166706605783. The reversal of 166706605778 is 877506607661.

It can be written as a sum of positive squares in 2 ways, for example, as 135105499489 + 31601106289 = 367567^2 + 177767^2 .

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4958375 + ... + 4991882.

Almost surely, 2^166706605778 is an apocalyptic number.

166706605778 is a deficient number, since it is larger than the sum of its proper divisors (83383178794).

166706605778 is an equidigital number, since it uses as much as digits as its factorization.

166706605778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9958636.

The product of its (nonzero) digits is 17781120, while the sum is 59.

The spelling of 166706605778 in words is "one hundred sixty-six billion, seven hundred six million, six hundred five thousand, seven hundred seventy-eight".