218220004 has 6 divisors (see below), whose sum is σ = 381885014. Its totient is φ = 109110000.

The previous prime is 218220001. The next prime is 218220019. The reversal of 218220004 is 400022812.

It can be written as a sum of positive squares in only one way, i.e., 217857600 + 362404 = 14760^2 + 602^2 .

It is not an unprimeable number, because it can be changed into a prime (218220001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27277497 + ... + 27277504.

Almost surely, 2^218220004 is an apocalyptic number.

It is an amenable number.

218220004 is a deficient number, since it is larger than the sum of its proper divisors (163665010).

218220004 is a wasteful number, since it uses less digits than its factorization.

218220004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54555005 (or 54555003 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 218220004 is about 14772.2714570238. The cubic root of 218220004 is about 602.0485569896.

Adding to 218220004 its reverse (400022812), we get a palindrome (618242816).

The spelling of 218220004 in words is "two hundred eighteen million, two hundred twenty thousand, four".