8445821 has 4 divisors (see below), whose sum is σ = 8942652. Its totient is φ = 7948992.

The previous prime is 8445799. The next prime is 8445841. The reversal of 8445821 is 1285448.

It is a happy number.

8445821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 4778596 + 3667225 = 2186^2 + 1915^2 .

It is a cyclic number.

It is not a de Polignac number, because 8445821 - 2¹⁴ = 8429437 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8445841) 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, 248390 + ... + 248423.

It is an arithmetic number, because the mean of its divisors is an integer number (2235663).

Almost surely, 2^8445821 is an apocalyptic number.

It is an amenable number.

8445821 is a deficient number, since it is larger than the sum of its proper divisors (496831).

8445821 is a wasteful number, since it uses less digits than its factorization.

8445821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496830.

The product of its digits is 10240, while the sum is 32.

The square root of 8445821 is about 2906.1694720026. The cubic root of 8445821 is about 203.6482227205.

The spelling of 8445821 in words is "eight million, four hundred forty-five thousand, eight hundred twenty-one".