2021213081 has 2 divisors, whose sum is σ = 2021213082. Its totient is φ = 2021213080.

The previous prime is 2021213059. The next prime is 2021213083. The reversal of 2021213081 is 1803121202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1914937600 + 106275481 = 43760^2 + 10309^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021213081 - 2¹⁰ = 2021212057 is a prime.

It is a super-2 number, since 2×2021213081² = 8170604637611025122, which contains 22 as substring.

Together with 2021213083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2021213083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010606540 + 1010606541.

It is an arithmetic number, because the mean of its divisors is an integer number (1010606541).

Almost surely, 2^2021213081 is an apocalyptic number.

It is an amenable number.

2021213081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021213081 is an equidigital number, since it uses as much as digits as its factorization.

2021213081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 2021213081 is about 44957.9034319885. The cubic root of 2021213081 is about 1264.3598610936.

Adding to 2021213081 its reverse (1803121202), we get a palindrome (3824334283).

The spelling of 2021213081 in words is "two billion, twenty-one million, two hundred thirteen thousand, eighty-one".