218364281 has 2 divisors, whose sum is σ = 218364282. Its totient is φ = 218364280.

The previous prime is 218364203. The next prime is 218364301. The reversal of 218364281 is 182463812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124099600 + 94264681 = 11140^2 + 9709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218364281 is a prime.

It is a super-4 number, since 4×218364281⁴ (a number of 34 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (218364481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109182140 + 109182141.

It is an arithmetic number, because the mean of its divisors is an integer number (109182141).

Almost surely, 2^218364281 is an apocalyptic number.

It is an amenable number.

218364281 is a deficient number, since it is larger than the sum of its proper divisors (1).

218364281 is an equidigital number, since it uses as much as digits as its factorization.

218364281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 35.

The square root of 218364281 is about 14777.1540223414. The cubic root of 218364281 is about 602.1812100035.

The spelling of 218364281 in words is "two hundred eighteen million, three hundred sixty-four thousand, two hundred eighty-one".