2018720221 has 16 divisors (see below), whose sum is σ = 2336752000. Its totient is φ = 1708216128.

The previous prime is 2018720203. The next prime is 2018720257. The reversal of 2018720221 is 1220278102.

It is a cyclic number.

It is not a de Polignac number, because 2018720221 - 2¹¹ = 2018718173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2018720261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211255 + ... + 220603.

It is an arithmetic number, because the mean of its divisors is an integer number (146047000).

Almost surely, 2^2018720221 is an apocalyptic number.

It is an amenable number.

2018720221 is a deficient number, since it is larger than the sum of its proper divisors (318031779).

2018720221 is a wasteful number, since it uses less digits than its factorization.

2018720221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9748.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 2018720221 is about 44930.1704982298. The cubic root of 2018720221 is about 1263.8398484954.

Adding to 2018720221 its reverse (1220278102), we get a palindrome (3238998323).

The spelling of 2018720221 in words is "two billion, eighteen million, seven hundred twenty thousand, two hundred twenty-one".