82021399 has 2 divisors, whose sum is σ = 82021400. Its totient is φ = 82021398.

The previous prime is 82021351. The next prime is 82021403. The reversal of 82021399 is 99312028.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 82021399 - 2¹¹ = 82019351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82021349) 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, 41010699 + 41010700.

It is an arithmetic number, because the mean of its divisors is an integer number (41010700).

Almost surely, 2^82021399 is an apocalyptic number.

82021399 is a deficient number, since it is larger than the sum of its proper divisors (1).

82021399 is an equidigital number, since it uses as much as digits as its factorization.

82021399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 82021399 is about 9056.5666231746. The cubic root of 82021399 is about 434.4859369807.

The spelling of 82021399 in words is "eighty-two million, twenty-one thousand, three hundred ninety-nine".