2221921 has 8 divisors (see below), whose sum is σ = 2429504. Its totient is φ = 2019600.

The previous prime is 2221909. The next prime is 2221931. The reversal of 2221921 is 1291222.

2221921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2221921 - 2⁵ = 2221889 is a prime.

It is a Duffinian number.

2221921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2221931) 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 7 ways as a sum of consecutive naturals, for example, 405 + ... + 2146.

It is an arithmetic number, because the mean of its divisors is an integer number (303688).

2^2221921 is an apocalyptic number.

It is an amenable number.

2221921 is a deficient number, since it is larger than the sum of its proper divisors (207583).

2221921 is a wasteful number, since it uses less digits than its factorization.

2221921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2631.

The product of its digits is 144, while the sum is 19.

The square root of 2221921 is about 1490.6109485711. The cubic root of 2221921 is about 130.4896915469.

The spelling of 2221921 in words is "two million, two hundred twenty-one thousand, nine hundred twenty-one".