2220918821 has 12 divisors (see below), whose sum is σ = 2507157996. Its totient is φ = 1964445120.

The previous prime is 2220918809. The next prime is 2220918823. The reversal of 2220918821 is 1288190222.

It can be written as a sum of positive squares in 2 ways, for example, as 1865030596 + 355888225 = 43186^2 + 18865^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2220918821 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 (2220918823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 243560 + ... + 252513.

It is an arithmetic number, because the mean of its divisors is an integer number (208929833).

Almost surely, 2^2220918821 is an apocalyptic number.

It is an amenable number.

2220918821 is a deficient number, since it is larger than the sum of its proper divisors (286239175).

2220918821 is a wasteful number, since it uses less digits than its factorization.

2220918821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496132 (or 496121 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 2220918821 is about 47126.6253937198. The cubic root of 2220918821 is about 1304.7006983290.

The spelling of 2220918821 in words is "two billion, two hundred twenty million, nine hundred eighteen thousand, eight hundred twenty-one".