218916193 has 2 divisors, whose sum is σ = 218916194. Its totient is φ = 218916192.

The previous prime is 218916169. The next prime is 218916197. The reversal of 218916193 is 391619812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151216209 + 67699984 = 12297^2 + 8228^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218916193 is a prime.

It is a super-2 number, since 2×218916193² = 95848599115226498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (218916197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109458096 + 109458097.

It is an arithmetic number, because the mean of its divisors is an integer number (109458097).

Almost surely, 2^218916193 is an apocalyptic number.

It is an amenable number.

218916193 is a deficient number, since it is larger than the sum of its proper divisors (1).

218916193 is an equidigital number, since it uses as much as digits as its factorization.

218916193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 40.

The square root of 218916193 is about 14795.8167398762. The cubic root of 218916193 is about 602.6881174261.

The spelling of 218916193 in words is "two hundred eighteen million, nine hundred sixteen thousand, one hundred ninety-three".