5220821 has 4 divisors (see below), whose sum is σ = 5233644. Its totient is φ = 5208000.

The previous prime is 5220799. The next prime is 5220823. The reversal of 5220821 is 1280225.

5220821 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 662596 + 4558225 = 814^2 + 2135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5220821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 5220793 and 5220802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5220823) 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, 5780 + ... + 6621.

It is an arithmetic number, because the mean of its divisors is an integer number (1308411).

Almost surely, 2^5220821 is an apocalyptic number.

It is an amenable number.

5220821 is a deficient number, since it is larger than the sum of its proper divisors (12823).

5220821 is a wasteful number, since it uses less digits than its factorization.

5220821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12822.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 5220821 is about 2284.9115956640. The cubic root of 5220821 is about 173.4787434475.

The spelling of 5220821 in words is "five million, two hundred twenty thousand, eight hundred twenty-one".