218641343281 has 3 divisors (see below), whose sum is σ = 218641810873. Its totient is φ = 218640875690.

The previous prime is 218641343273. The next prime is 218641343287. The reversal of 218641343281 is 182343146812.

The square root of 218641343281 is 467591.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 218641343281 - 2³ = 218641343273 is a prime.

It is a super-2 number, since 2×218641343281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218641343287) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 233796 + ... + 701386.

Almost surely, 2^218641343281 is an apocalyptic number.

218641343281 is the 467591-st square number.

218641343281 is the 233796-th centered octagonal number.

It is an amenable number.

218641343281 is a deficient number, since it is larger than the sum of its proper divisors (467592).

218641343281 is an frugal number, since it uses more digits than its factorization.

218641343281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935182 (or 467591 counting only the distinct ones).

The product of its digits is 221184, while the sum is 43.

The spelling of 218641343281 in words is "two hundred eighteen billion, six hundred forty-one million, three hundred forty-three thousand, two hundred eighty-one".