3020821 has 4 divisors (see below), whose sum is σ = 3026700. Its totient is φ = 3014944.

The previous prime is 3020819. The next prime is 3020827. The reversal of 3020821 is 1280203.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1280203 = 23 ⋅55661.

It can be written as a sum of positive squares in 2 ways, for example, as 168100 + 2852721 = 410^2 + 1689^2 .

It is a cyclic number.

It is not a de Polignac number, because 3020821 - 2¹ = 3020819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3020795 and 3020804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3020827) 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, 2086 + ... + 3223.

It is an arithmetic number, because the mean of its divisors is an integer number (756675).

Almost surely, 2^3020821 is an apocalyptic number.

It is an amenable number.

3020821 is a deficient number, since it is larger than the sum of its proper divisors (5879).

3020821 is an equidigital number, since it uses as much as digits as its factorization.

3020821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5878.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 3020821 is about 1738.0509198525. The cubic root of 3020821 is about 144.5578445233.

The spelling of 3020821 in words is "three million, twenty thousand, eight hundred twenty-one".