218944393 has 8 divisors (see below), whose sum is σ = 221200128. Its totient is φ = 216694464.

The previous prime is 218944357. The next prime is 218944399. The reversal of 218944393 is 393449812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218944393 - 2²⁵ = 185389961 is a prime.

It is a super-2 number, since 2×218944393² = 95873294452276898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218944399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146496 + ... + 147982.

It is an arithmetic number, because the mean of its divisors is an integer number (27650016).

Almost surely, 2^218944393 is an apocalyptic number.

It is an amenable number.

218944393 is a deficient number, since it is larger than the sum of its proper divisors (2255735).

218944393 is a wasteful number, since it uses less digits than its factorization.

218944393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2903.

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

The square root of 218944393 is about 14796.7696812514. The cubic root of 218944393 is about 602.7139950233.

The spelling of 218944393 in words is "two hundred eighteen million, nine hundred forty-four thousand, three hundred ninety-three".