166408865865 has 48 divisors (see below), whose sum is σ = 318974572800. Its totient is φ = 79577821440.

The previous prime is 166408865851. The next prime is 166408865867. The reversal of 166408865865 is 568568804661.

166408865865 is a `hidden beast` number, since 1 + 6 + 6 + 40 + 8 + 8 + 6 + 586 + 5 = 666.

It is not a de Polignac number, because 166408865865 - 2¹⁶ = 166408800329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166408865867) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2266465 + ... + 2338734.

It is an arithmetic number, because the mean of its divisors is an integer number (6645303600).

Almost surely, 2^166408865865 is an apocalyptic number.

166408865865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166408865865 is a deficient number, since it is larger than the sum of its proper divisors (152565706935).

166408865865 is a wasteful number, since it uses less digits than its factorization.

166408865865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4605294 (or 4605291 counting only the distinct ones).

The product of its (nonzero) digits is 66355200, while the sum is 63.

The spelling of 166408865865 in words is "one hundred sixty-six billion, four hundred eight million, eight hundred sixty-five thousand, eight hundred sixty-five".