218445328685 has 8 divisors (see below), whose sum is σ = 262369078296. Its totient is φ = 174599807040.

The previous prime is 218445328669. The next prime is 218445328687. The reversal of 218445328685 is 586823544812.

It can be written as a sum of positive squares in 4 ways, for example, as 7303240681 + 211142088004 = 85459^2 + 459502^2 .

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

It is not a de Polignac number, because 218445328685 - 2⁴ = 218445328669 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218445328685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218445328687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19550846 + ... + 19562015.

It is an arithmetic number, because the mean of its divisors is an integer number (32796134787).

Almost surely, 2^218445328685 is an apocalyptic number.

It is an amenable number.

218445328685 is a deficient number, since it is larger than the sum of its proper divisors (43923749611).

218445328685 is a wasteful number, since it uses less digits than its factorization.

218445328685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39113983.

The product of its digits is 14745600, while the sum is 56.

The spelling of 218445328685 in words is "two hundred eighteen billion, four hundred forty-five million, three hundred twenty-eight thousand, six hundred eighty-five".