218764633217 has 8 divisors (see below), whose sum is σ = 240037827624. Its totient is φ = 198126459648.

The previous prime is 218764633211. The next prime is 218764633261. The reversal of 218764633217 is 712336467812.

218764633217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 17508317761 + 201256315456 = 132319^2 + 448616^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 218764633217 - 2¹² = 218764629121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218764633211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 158754488 + ... + 158755865.

It is an arithmetic number, because the mean of its divisors is an integer number (30004728453).

Almost surely, 2^218764633217 is an apocalyptic number.

It is an amenable number.

218764633217 is a deficient number, since it is larger than the sum of its proper divisors (21273194407).

218764633217 is a wasteful number, since it uses less digits than its factorization.

218764633217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317510419.

The product of its digits is 2032128, while the sum is 50.

The spelling of 218764633217 in words is "two hundred eighteen billion, seven hundred sixty-four million, six hundred thirty-three thousand, two hundred seventeen".