2021109993809 has 2 divisors, whose sum is σ = 2021109993810. Its totient is φ = 2021109993808.

The previous prime is 2021109993787. The next prime is 2021109993863. The reversal of 2021109993809 is 9083999011202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1994040531025 + 27069462784 = 1412105^2 + 164528^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021109993809 - 2¹⁶ = 2021109928273 is a prime.

It is not a weakly prime, because it can be changed into another prime (2021109992809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010554996904 + 1010554996905.

It is an arithmetic number, because the mean of its divisors is an integer number (1010554996905).

Almost surely, 2^{2021109993809} is an apocalyptic number.

It is an amenable number.

2021109993809 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021109993809 is an equidigital number, since it uses as much as digits as its factorization.

2021109993809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 629856, while the sum is 53.

The spelling of 2021109993809 in words is "two trillion, twenty-one billion, one hundred nine million, nine hundred ninety-three thousand, eight hundred nine".