218704473257 has 2 divisors, whose sum is σ = 218704473258. Its totient is φ = 218704473256.

The previous prime is 218704473241. The next prime is 218704473287. The reversal of 218704473257 is 752374407812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217943320336 + 761152921 = 466844^2 + 27589^2 .

It is a cyclic number.

It is not a de Polignac number, because 218704473257 - 2⁴ = 218704473241 is a prime.

It is not a weakly prime, because it can be changed into another prime (218704473287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109352236628 + 109352236629.

It is an arithmetic number, because the mean of its divisors is an integer number (109352236629).

Almost surely, 2^218704473257 is an apocalyptic number.

It is an amenable number.

218704473257 is a deficient number, since it is larger than the sum of its proper divisors (1).

218704473257 is an equidigital number, since it uses as much as digits as its factorization.

218704473257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2634240, while the sum is 50.

The spelling of 218704473257 in words is "two hundred eighteen billion, seven hundred four million, four hundred seventy-three thousand, two hundred fifty-seven".