218107021 has 8 divisors (see below), whose sum is σ = 238521600. Its totient is φ = 197790240.

The previous prime is 218107013. The next prime is 218107039. The reversal of 218107021 is 120701812.

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

It is a cyclic number.

It is not a de Polignac number, because 218107021 - 2³ = 218107013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 218106983 and 218107001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218107121) 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, 19741 + ... + 28738.

It is an arithmetic number, because the mean of its divisors is an integer number (29815200).

Almost surely, 2^218107021 is an apocalyptic number.

It is an amenable number.

218107021 is a deficient number, since it is larger than the sum of its proper divisors (20414579).

218107021 is a wasteful number, since it uses less digits than its factorization.

218107021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48899.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 218107021 is about 14768.4468039127. The cubic root of 218107021 is about 601.9446358801.

Adding to 218107021 its reverse (120701812), we get a palindrome (338808833).

The spelling of 218107021 in words is "two hundred eighteen million, one hundred seven thousand, twenty-one".