218838381 has 8 divisors (see below), whose sum is σ = 295300320. Its totient is φ = 144134352.

The previous prime is 218838377. The next prime is 218838383. The reversal of 218838381 is 183838812.

It is a happy number.

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

It is not a de Polignac number, because 218838381 - 2² = 218838377 is a prime.

It is a super-2 number, since 2×218838381² = 95780473997402322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218838383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 439186 + ... + 439683.

It is an arithmetic number, because the mean of its divisors is an integer number (36912540).

Almost surely, 2^218838381 is an apocalyptic number.

It is an amenable number.

218838381 is a deficient number, since it is larger than the sum of its proper divisors (76461939).

218838381 is an equidigital number, since it uses as much as digits as its factorization.

218838381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878955.

The product of its digits is 73728, while the sum is 42.

The square root of 218838381 is about 14793.1869791469. The cubic root of 218838381 is about 602.6167020829.

The spelling of 218838381 in words is "two hundred eighteen million, eight hundred thirty-eight thousand, three hundred eighty-one".