82775221 has 2 divisors, whose sum is σ = 82775222. Its totient is φ = 82775220.

The previous prime is 82775219. The next prime is 82775233. The reversal of 82775221 is 12257728.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81540900 + 1234321 = 9030^2 + 1111^2 .

It is a cyclic number.

It is not a de Polignac number, because 82775221 - 2¹ = 82775219 is a prime.

Together with 82775219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82775201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41387610 + 41387611.

It is an arithmetic number, because the mean of its divisors is an integer number (41387611).

Almost surely, 2^82775221 is an apocalyptic number.

It is an amenable number.

82775221 is a deficient number, since it is larger than the sum of its proper divisors (1).

82775221 is an equidigital number, since it uses as much as digits as its factorization.

82775221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15680, while the sum is 34.

The square root of 82775221 is about 9098.0888652508. The cubic root of 82775221 is about 435.8129352808.

The spelling of 82775221 in words is "eighty-two million, seven hundred seventy-five thousand, two hundred twenty-one".