2221816656 has 80 divisors (see below), whose sum is σ = 5792129280. Its totient is φ = 733877760.

The previous prime is 2221816601. The next prime is 2221816673. The reversal of 2221816656 is 6566181222.

It is a super-3 number, since 3×2221816656³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3360966 + ... + 3361626.

It is an arithmetic number, because the mean of its divisors is an integer number (72401616).

Almost surely, 2^2221816656 is an apocalyptic number.

It is an amenable number.

2221816656 is an abundant number, since it is smaller than the sum of its proper divisors (3570312624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2221816656 is a wasteful number, since it uses less digits than its factorization.

2221816656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1204 (or 1198 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 2221816656 is about 47136.1502034267. The cubic root of 2221816656 is about 1304.8764886556.

Adding to 2221816656 its reverse (6566181222), we get a palindrome (8787997878).

The spelling of 2221816656 in words is "two billion, two hundred twenty-one million, eight hundred sixteen thousand, six hundred fifty-six".