2021311309 has 2 divisors, whose sum is σ = 2021311310. Its totient is φ = 2021311308.

The previous prime is 2021311291. The next prime is 2021311337. The reversal of 2021311309 is 9031131202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2003010025 + 18301284 = 44755^2 + 4278^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021311309 - 2¹⁷ = 2021180237 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021311309.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021311379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010655654 + 1010655655.

It is an arithmetic number, because the mean of its divisors is an integer number (1010655655).

Almost surely, 2^2021311309 is an apocalyptic number.

It is an amenable number.

2021311309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021311309 is an equidigital number, since it uses as much as digits as its factorization.

2021311309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 2021311309 is about 44958.9958628971. The cubic root of 2021311309 is about 1264.3803427752.

The spelling of 2021311309 in words is "two billion, twenty-one million, three hundred eleven thousand, three hundred nine".