218361381 has 8 divisors (see below), whose sum is σ = 332741184. Its totient is φ = 124777920.

The previous prime is 218361373. The next prime is 218361401. The reversal of 218361381 is 183163812.

218361381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 218361381 - 2³ = 218361373 is a prime.

It is a super-2 number, since 2×218361381² = 95363385424454322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218361361) 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, 5199060 + ... + 5199101.

It is an arithmetic number, because the mean of its divisors is an integer number (41592648).

Almost surely, 2^218361381 is an apocalyptic number.

218361381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

218361381 is a deficient number, since it is larger than the sum of its proper divisors (114379803).

218361381 is a wasteful number, since it uses less digits than its factorization.

218361381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10398171.

The product of its digits is 6912, while the sum is 33.

The square root of 218361381 is about 14777.0558975731. The cubic root of 218361381 is about 602.1785442237.

It can be divided in two parts, 21 and 8361381, that multiplied together give a square (175589001 = 13251²).

The spelling of 218361381 in words is "two hundred eighteen million, three hundred sixty-one thousand, three hundred eighty-one".