2218521621 has 16 divisors (see below), whose sum is σ = 3015465984. Its totient is φ = 1450491504.

The previous prime is 2218521587. The next prime is 2218521667. The reversal of 2218521621 is 1261258122.

It is not a de Polignac number, because 2218521621 - 2¹¹ = 2218519573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2218521671) 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, 21316 + ... + 69938.

It is an arithmetic number, because the mean of its divisors is an integer number (188466624).

Almost surely, 2^2218521621 is an apocalyptic number.

It is an amenable number.

2218521621 is a deficient number, since it is larger than the sum of its proper divisors (796944363).

2218521621 is a wasteful number, since it uses less digits than its factorization.

2218521621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48920.

The product of its digits is 3840, while the sum is 30.

The square root of 2218521621 is about 47101.1849214009. The cubic root of 2218521621 is about 1304.2311097287.

Adding to 2218521621 its reverse (1261258122), we get a palindrome (3479779743).

The spelling of 2218521621 in words is "two billion, two hundred eighteen million, five hundred twenty-one thousand, six hundred twenty-one".