218506690193 has 4 divisors (see below), whose sum is σ = 238370934768. Its totient is φ = 198642445620.

The previous prime is 218506690187. The next prime is 218506690271. The reversal of 218506690193 is 391096605812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218506690193 - 2²⁸ = 218238254737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218506690133) 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, 9932122271 + ... + 9932122292.

It is an arithmetic number, because the mean of its divisors is an integer number (59592733692).

Almost surely, 2^218506690193 is an apocalyptic number.

It is an amenable number.

218506690193 is a deficient number, since it is larger than the sum of its proper divisors (19864244575).

218506690193 is a wasteful number, since it uses less digits than its factorization.

218506690193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19864244574.

The product of its (nonzero) digits is 699840, while the sum is 50.

The spelling of 218506690193 in words is "two hundred eighteen billion, five hundred six million, six hundred ninety thousand, one hundred ninety-three".