163891980218 has 4 divisors (see below), whose sum is σ = 245837970330. Its totient is φ = 81945990108.

The previous prime is 163891980209. The next prime is 163891980269. The reversal of 163891980218 is 812089198361.

163891980218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 134158840729 + 29733139489 = 366277^2 + 172433^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40972995053 + ... + 40972995056.

Almost surely, 2^163891980218 is an apocalyptic number.

163891980218 is a deficient number, since it is larger than the sum of its proper divisors (81945990112).

163891980218 is an equidigital number, since it uses as much as digits as its factorization.

163891980218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81945990111.

The product of its (nonzero) digits is 1492992, while the sum is 56.

The spelling of 163891980218 in words is "one hundred sixty-three billion, eight hundred ninety-one million, nine hundred eighty thousand, two hundred eighteen".