2218221 has 6 divisors (see below), whose sum is σ = 3204110. Its totient is φ = 1478808.

The previous prime is 2218219. The next prime is 2218277. The reversal of 2218221 is 1228122.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2205225 + 12996 = 1485^2 + 114^2 .

It is not a de Polignac number, because 2218221 - 2¹ = 2218219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2218194 and 2218203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2218201) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 123226 + ... + 123243.

2^2218221 is an apocalyptic number.

It is an amenable number.

2218221 is a deficient number, since it is larger than the sum of its proper divisors (985889).

2218221 is a wasteful number, since it uses less digits than its factorization.

2218221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246475 (or 246472 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 2218221 is about 1489.3693296157. The cubic root of 2218221 is about 130.4172197077.

Subtracting from 2218221 its reverse (1228122), we obtain a palindrome (990099).

The spelling of 2218221 in words is "two million, two hundred eighteen thousand, two hundred twenty-one".