218638485 has 48 divisors (see below), whose sum is σ = 412439664. Its totient is φ = 106500096.

The previous prime is 218638481. The next prime is 218638489. The reversal of 218638485 is 584836812.

218638485 is a `hidden beast` number, since 2 + 1 + 8 + 638 + 4 + 8 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (218638481) and next prime (218638489).

It can be written as a sum of positive squares in 8 ways, for example, as 603729 + 218034756 = 777^2 + 14766^2 .

It is not a de Polignac number, because 218638485 - 2² = 218638481 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 218638485.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218638481) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 54819 + ... + 58671.

It is an arithmetic number, because the mean of its divisors is an integer number (8592493).

Almost surely, 2^218638485 is an apocalyptic number.

It is an amenable number.

218638485 is a deficient number, since it is larger than the sum of its proper divisors (193801179).

218638485 is a wasteful number, since it uses less digits than its factorization.

218638485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3974 (or 3971 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The square root of 218638485 is about 14786.4290821009. The cubic root of 218638485 is about 602.4331612063.

The spelling of 218638485 in words is "two hundred eighteen million, six hundred thirty-eight thousand, four hundred eighty-five".