218281361 has 4 divisors (see below), whose sum is σ = 218311152. Its totient is φ = 218251572.

The previous prime is 218281351. The next prime is 218281379. The reversal of 218281361 is 163182812.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 218281361 - 2²² = 214087057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218281351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4610 + ... + 21396.

It is an arithmetic number, because the mean of its divisors is an integer number (54577788).

Almost surely, 2^218281361 is an apocalyptic number.

It is an amenable number.

218281361 is a deficient number, since it is larger than the sum of its proper divisors (29791).

218281361 is a wasteful number, since it uses less digits than its factorization.

218281361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29790.

The product of its digits is 4608, while the sum is 32.

The square root of 218281361 is about 14774.3480736038. The cubic root of 218281361 is about 602.1049777745.

The spelling of 218281361 in words is "two hundred eighteen million, two hundred eighty-one thousand, three hundred sixty-one".