218996471 has 2 divisors, whose sum is σ = 218996472. Its totient is φ = 218996470.

The previous prime is 218996461. The next prime is 218996473. The reversal of 218996471 is 174699812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218996471 is a prime.

It is a super-3 number, since 3×218996471³ (a number of 26 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 218996473, 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 (218996473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109498235 + 109498236.

It is an arithmetic number, because the mean of its divisors is an integer number (109498236).

Almost surely, 2^218996471 is an apocalyptic number.

218996471 is a deficient number, since it is larger than the sum of its proper divisors (1).

218996471 is an equidigital number, since it uses as much as digits as its factorization.

218996471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The square root of 218996471 is about 14798.5293526080. The cubic root of 218996471 is about 602.7617783146.

The spelling of 218996471 in words is "two hundred eighteen million, nine hundred ninety-six thousand, four hundred seventy-one".