4227821 has 4 divisors (see below), whose sum is σ = 4553052. Its totient is φ = 3902592.

The previous prime is 4227809. The next prime is 4227827. The reversal of 4227821 is 1287224.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 346921 + 3880900 = 589^2 + 1970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4227821 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 (4227827) 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, 162596 + ... + 162621.

It is an arithmetic number, because the mean of its divisors is an integer number (1138263).

Almost surely, 2^4227821 is an apocalyptic number.

It is an amenable number.

4227821 is a deficient number, since it is larger than the sum of its proper divisors (325231).

4227821 is a wasteful number, since it uses less digits than its factorization.

4227821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325230.

The product of its digits is 1792, while the sum is 26.

The square root of 4227821 is about 2056.1665788549. The cubic root of 4227821 is about 161.6983284901.

The spelling of 4227821 in words is "four million, two hundred twenty-seven thousand, eight hundred twenty-one".