2021779 has 2 divisors, whose sum is σ = 2021780. Its totient is φ = 2021778.

The previous prime is 2021777. The next prime is 2021783. The reversal of 2021779 is 9771202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2021779 - 2¹ = 2021777 is a prime.

Together with 2021777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2021777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010889 + 1010890.

It is an arithmetic number, because the mean of its divisors is an integer number (1010890).

2^2021779 is an apocalyptic number.

2021779 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021779 is an equidigital number, since it uses as much as digits as its factorization.

2021779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 2021779 is about 1421.8927526364. The cubic root of 2021779 is about 126.4477852694.

The spelling of 2021779 in words is "two million, twenty-one thousand, seven hundred seventy-nine".