218197643 has 2 divisors, whose sum is σ = 218197644. Its totient is φ = 218197642.

The previous prime is 218197633. The next prime is 218197667. The reversal of 218197643 is 346791812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 218197643 - 2¹⁸ = 217935499 is a prime.

It is a super-2 number, since 2×218197643² = 95220422821510898, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 218197643.

It is not a weakly prime, because it can be changed into another prime (218197633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109098821 + 109098822.

It is an arithmetic number, because the mean of its divisors is an integer number (109098822).

Almost surely, 2^218197643 is an apocalyptic number.

218197643 is a deficient number, since it is larger than the sum of its proper divisors (1).

218197643 is an equidigital number, since it uses as much as digits as its factorization.

218197643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 41.

The square root of 218197643 is about 14771.5145804349. The cubic root of 218197643 is about 602.0279923187.

The spelling of 218197643 in words is "two hundred eighteen million, one hundred ninety-seven thousand, six hundred forty-three".