2221155640 has 128 divisors (see below), whose sum is σ = 5559114240. Its totient is φ = 792000000.

The previous prime is 2221155637. The next prime is 2221155649. The reversal of 2221155640 is 465511222.

It is a junction number, because it is equal to n+sod(n) for n = 2221155599 and 2221155608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221155649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6710275 + ... + 6710605.

It is an arithmetic number, because the mean of its divisors is an integer number (43430580).

Almost surely, 2^2221155640 is an apocalyptic number.

2221155640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2221155640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2779557120).

2221155640 is an abundant number, since it is smaller than the sum of its proper divisors (3337958600).

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

2221155640 is a wasteful number, since it uses less digits than its factorization.

2221155640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 2221155640 is about 47129.1379085168. The cubic root of 2221155640 is about 1304.7470705677.

Adding to 2221155640 its reverse (465511222), we get a palindrome (2686666862).

The spelling of 2221155640 in words is "two billion, two hundred twenty-one million, one hundred fifty-five thousand, six hundred forty".