218805541 has 2 divisors, whose sum is σ = 218805542. Its totient is φ = 218805540.

The previous prime is 218805529. The next prime is 218805547. The reversal of 218805541 is 145508812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174636225 + 44169316 = 13215^2 + 6646^2 .

It is a cyclic number.

It is not a de Polignac number, because 218805541 - 2⁷ = 218805413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 218805497 and 218805506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218805547) 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, 109402770 + 109402771.

It is an arithmetic number, because the mean of its divisors is an integer number (109402771).

Almost surely, 2^218805541 is an apocalyptic number.

It is an amenable number.

218805541 is a deficient number, since it is larger than the sum of its proper divisors (1).

218805541 is an equidigital number, since it uses as much as digits as its factorization.

218805541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12800, while the sum is 34.

The square root of 218805541 is about 14792.0769670794. The cubic root of 218805541 is about 602.5865566662.

The spelling of 218805541 in words is "two hundred eighteen million, eight hundred five thousand, five hundred forty-one".