82021789 has 2 divisors, whose sum is σ = 82021790. Its totient is φ = 82021788.

The previous prime is 82021783. The next prime is 82021801. The reversal of 82021789 is 98712028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81812025 + 209764 = 9045^2 + 458^2 .

It is a cyclic number.

It is not a de Polignac number, because 82021789 - 2⁵ = 82021757 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82021783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41010894 + 41010895.

It is an arithmetic number, because the mean of its divisors is an integer number (41010895).

Almost surely, 2^82021789 is an apocalyptic number.

It is an amenable number.

82021789 is a deficient number, since it is larger than the sum of its proper divisors (1).

82021789 is an equidigital number, since it uses as much as digits as its factorization.

82021789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 82021789 is about 9056.5881544873. The cubic root of 82021789 is about 434.4866256191.

The spelling of 82021789 in words is "eighty-two million, twenty-one thousand, seven hundred eighty-nine".