2187221 has 4 divisors (see below), whose sum is σ = 2191200. Its totient is φ = 2183244.

The previous prime is 2187217. The next prime is 2187233. The reversal of 2187221 is 1227812.

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 a cyclic number.

It is not a de Polignac number, because 2187221 - 2² = 2187217 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 (2187121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1001 + ... + 2318.

It is an arithmetic number, because the mean of its divisors is an integer number (547800).

2^2187221 is an apocalyptic number.

It is an amenable number.

2187221 is a deficient number, since it is larger than the sum of its proper divisors (3979).

2187221 is an equidigital number, since it uses as much as digits as its factorization.

2187221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3978.

The product of its digits is 448, while the sum is 23.

The square root of 2187221 is about 1478.9256235524. The cubic root of 2187221 is about 129.8068334322.

The spelling of 2187221 in words is "two million, one hundred eighty-seven thousand, two hundred twenty-one".