218142389 has 2 divisors, whose sum is σ = 218142390. Its totient is φ = 218142388.

The previous prime is 218142377. The next prime is 218142451. The reversal of 218142389 is 983241812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179292100 + 38850289 = 13390^2 + 6233^2 .

It is a cyclic number.

It is not a de Polignac number, because 218142389 - 2¹² = 218138293 is a prime.

It is a super-2 number, since 2×218142389² = 95172203757254642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218142359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109071194 + 109071195.

It is an arithmetic number, because the mean of its divisors is an integer number (109071195).

Almost surely, 2^218142389 is an apocalyptic number.

It is an amenable number.

218142389 is a deficient number, since it is larger than the sum of its proper divisors (1).

218142389 is an equidigital number, since it uses as much as digits as its factorization.

218142389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 38.

The square root of 218142389 is about 14769.6441731004. The cubic root of 218142389 is about 601.9771710198.

The spelling of 218142389 in words is "two hundred eighteen million, one hundred forty-two thousand, three hundred eighty-nine".