166918947 has 8 divisors (see below), whose sum is σ = 239678544. Its totient is φ = 102719328.

The previous prime is 166918943. The next prime is 166918957. The reversal of 166918947 is 749819661.

It is a happy number.

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

It is not a de Polignac number, because 166918947 - 2² = 166918943 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166918947.

It is not an unprimeable number, because it can be changed into a prime (166918943) 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 7 ways as a sum of consecutive naturals, for example, 2139948 + ... + 2140025.

It is an arithmetic number, because the mean of its divisors is an integer number (29959818).

Almost surely, 2^166918947 is an apocalyptic number.

166918947 is a deficient number, since it is larger than the sum of its proper divisors (72759597).

166918947 is a wasteful number, since it uses less digits than its factorization.

166918947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4279989.

The product of its digits is 653184, while the sum is 51.

The square root of 166918947 is about 12919.7115679879. The cubic root of 166918947 is about 550.5987386009.

The spelling of 166918947 in words is "one hundred sixty-six million, nine hundred eighteen thousand, nine hundred forty-seven".