166861679 has 4 divisors (see below), whose sum is σ = 172615560. Its totient is φ = 161107800.

The previous prime is 166861663. The next prime is 166861687. The reversal of 166861679 is 976168661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 976168661 = 13 ⋅75089897.

It is a cyclic number.

It is not a de Polignac number, because 166861679 - 2⁴ = 166861663 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 (166861979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2876897 + ... + 2876954.

It is an arithmetic number, because the mean of its divisors is an integer number (43153890).

Almost surely, 2^166861679 is an apocalyptic number.

166861679 is a deficient number, since it is larger than the sum of its proper divisors (5753881).

166861679 is an equidigital number, since it uses as much as digits as its factorization.

166861679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5753880.

The product of its digits is 653184, while the sum is 50.

The square root of 166861679 is about 12917.4950745104. The cubic root of 166861679 is about 550.5357633348.

The spelling of 166861679 in words is "one hundred sixty-six million, eight hundred sixty-one thousand, six hundred seventy-nine".