218844389 has 2 divisors, whose sum is σ = 218844390. Its totient is φ = 218844388.

The previous prime is 218844371. The next prime is 218844391. The reversal of 218844389 is 983448812.

It is a happy number.

218844389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129390625 + 89453764 = 11375^2 + 9458^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218844389 is a prime.

Together with 218844391, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218844359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109422194 + 109422195.

It is an arithmetic number, because the mean of its divisors is an integer number (109422195).

Almost surely, 2^218844389 is an apocalyptic number.

It is an amenable number.

218844389 is a deficient number, since it is larger than the sum of its proper divisors (1).

218844389 is an equidigital number, since it uses as much as digits as its factorization.

218844389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 442368, while the sum is 47.

The square root of 218844389 is about 14793.3900442056. The cubic root of 218844389 is about 602.6222167889.

The spelling of 218844389 in words is "two hundred eighteen million, eight hundred forty-four thousand, three hundred eighty-nine".