2002820821 has 2 divisors, whose sum is σ = 2002820822. Its totient is φ = 2002820820.

The previous prime is 2002820819. The next prime is 2002820863. The reversal of 2002820821 is 1280282002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1862871921 + 139948900 = 43161^2 + 11830^2 .

It is a cyclic number.

It is not a de Polignac number, because 2002820821 - 2¹ = 2002820819 is a prime.

It is a super-2 number, since 2×2002820821² = 8022582482062228082, which contains 22 as substring.

Together with 2002820819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2002820891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1001410410 + 1001410411.

It is an arithmetic number, because the mean of its divisors is an integer number (1001410411).

Almost surely, 2^2002820821 is an apocalyptic number.

It is an amenable number.

2002820821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2002820821 is an equidigital number, since it uses as much as digits as its factorization.

2002820821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 2002820821 is about 44752.8861750837. The cubic root of 2002820821 is about 1260.5131069269.

The spelling of 2002820821 in words is "two billion, two million, eight hundred twenty thousand, eight hundred twenty-one".