163861666 has 16 divisors (see below), whose sum is σ = 252153720. Its totient is φ = 79816320.

The previous prime is 163861661. The next prime is 163861673. The reversal of 163861666 is 666168361.

It can be written as a sum of positive squares in 4 ways, for example, as 97911025 + 65950641 = 9895^2 + 8121^2 .

It is not an unprimeable number, because it can be changed into a prime (163861661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90700 + ... + 92488.

Almost surely, 2^163861666 is an apocalyptic number.

163861666 is a deficient number, since it is larger than the sum of its proper divisors (88292054).

163861666 is a wasteful number, since it uses less digits than its factorization.

163861666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2949.

The product of its digits is 186624, while the sum is 43.

The square root of 163861666 is about 12800.8463001475. The cubic root of 163861666 is about 547.2164218857.

The spelling of 163861666 in words is "one hundred sixty-three million, eight hundred sixty-one thousand, six hundred sixty-six".