2218521 has 4 divisors (see below), whose sum is σ = 2958032. Its totient is φ = 1479012.

The previous prime is 2218519. The next prime is 2218523. The reversal of 2218521 is 1258122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (2218519) and next prime (2218523).

It is not a de Polignac number, because 2218521 - 2¹ = 2218519 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2218523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 369751 + ... + 369756.

It is an arithmetic number, because the mean of its divisors is an integer number (739508).

2^2218521 is an apocalyptic number.

It is an amenable number.

2218521 is a deficient number, since it is larger than the sum of its proper divisors (739511).

2218521 is an equidigital number, since it uses as much as digits as its factorization.

2218521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 739510.

The product of its digits is 320, while the sum is 21.

The square root of 2218521 is about 1489.4700399807. The cubic root of 2218521 is about 130.4230988037.

The spelling of 2218521 in words is "two million, two hundred eighteen thousand, five hundred twenty-one".