218875861 has 2 divisors, whose sum is σ = 218875862. Its totient is φ = 218875860.

The previous prime is 218875837. The next prime is 218875873. The reversal of 218875861 is 168578812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137334961 + 81540900 = 11719^2 + 9030^2 .

It is a cyclic number.

It is not a de Polignac number, because 218875861 - 2⁵ = 218875829 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218875361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109437930 + 109437931.

It is an arithmetic number, because the mean of its divisors is an integer number (109437931).

Almost surely, 2^218875861 is an apocalyptic number.

It is an amenable number.

218875861 is a deficient number, since it is larger than the sum of its proper divisors (1).

218875861 is an equidigital number, since it uses as much as digits as its factorization.

218875861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 215040, while the sum is 46.

The square root of 218875861 is about 14794.4537242847. The cubic root of 218875861 is about 602.6511030939.

The spelling of 218875861 in words is "two hundred eighteen million, eight hundred seventy-five thousand, eight hundred sixty-one".