2287821 has 8 divisors (see below), whose sum is σ = 3133024. Its totient is φ = 1483920.

The previous prime is 2287811. The next prime is 2287823. The reversal of 2287821 is 1287822.

2287821 = T₃₃₃ + T₃₃₄ + ... + T₃₆₉.

It is a happy number.

2287821 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 not a de Polignac number, because 2287821 - 2¹⁰ = 2286797 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 (2287823) 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, 10195 + ... + 10416.

It is an arithmetic number, because the mean of its divisors is an integer number (391628).

2^2287821 is an apocalyptic number.

It is an amenable number.

2287821 is a deficient number, since it is larger than the sum of its proper divisors (845203).

2287821 is a wasteful number, since it uses less digits than its factorization.

2287821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20651.

The product of its digits is 3584, while the sum is 30.

The square root of 2287821 is about 1512.5544618294. The cubic root of 2287821 is about 131.7672090744.

Subtracting from 2287821 its reverse (1287822), we obtain a palindrome (999999).

The spelling of 2287821 in words is "two million, two hundred eighty-seven thousand, eight hundred twenty-one".