166603921508 has 12 divisors (see below), whose sum is σ = 296336483772. Its totient is φ = 81936354720.

The previous prime is 166603921507. The next prime is 166603921537. The reversal of 166603921508 is 805129306661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 37778919424 + 128825002084 = 194368^2 + 358922^2 .

It is not an unprimeable number, because it can be changed into a prime (166603921507) 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, 341401235 + ... + 341401722.

It is an arithmetic number, because the mean of its divisors is an integer number (24694706981).

Almost surely, 2^166603921508 is an apocalyptic number.

It is an amenable number.

166603921508 is a deficient number, since it is larger than the sum of its proper divisors (129732562264).

166603921508 is a wasteful number, since it uses less digits than its factorization.

166603921508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682803022 (or 682803020 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 47.

The spelling of 166603921508 in words is "one hundred sixty-six billion, six hundred three million, nine hundred twenty-one thousand, five hundred eight".