218219971 has 2 divisors, whose sum is σ = 218219972. Its totient is φ = 218219970.

The previous prime is 218219933. The next prime is 218220001. The reversal of 218219971 is 179912812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218219971 - 2⁹ = 218219459 is a prime.

It is not a weakly prime, because it can be changed into another prime (218219371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109109985 + 109109986.

It is an arithmetic number, because the mean of its divisors is an integer number (109109986).

Almost surely, 2^218219971 is an apocalyptic number.

218219971 is a deficient number, since it is larger than the sum of its proper divisors (1).

218219971 is an equidigital number, since it uses as much as digits as its factorization.

218219971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 40.

The square root of 218219971 is about 14772.2703400662. The cubic root of 218219971 is about 602.0485266416.

The spelling of 218219971 in words is "two hundred eighteen million, two hundred nineteen thousand, nine hundred seventy-one".