218161678891 has 32 divisors (see below), whose sum is σ = 240330888000. Its totient is φ = 196828059648.

The previous prime is 218161678879. The next prime is 218161678907. The reversal of 218161678891 is 198876161812.

218161678891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 218161678891 - 2¹⁷ = 218161547819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218161678391) by changing a digit.

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 in 31 ways as a sum of consecutive naturals, for example, 35825775 + ... + 35831863.

It is an arithmetic number, because the mean of its divisors is an integer number (7510340250).

Almost surely, 2^218161678891 is an apocalyptic number.

218161678891 is a deficient number, since it is larger than the sum of its proper divisors (22169209109).

218161678891 is a wasteful number, since it uses less digits than its factorization.

218161678891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6543.

The product of its digits is 2322432, while the sum is 58.

The spelling of 218161678891 in words is "two hundred eighteen billion, one hundred sixty-one million, six hundred seventy-eight thousand, eight hundred ninety-one".