82397221 has 2 divisors, whose sum is σ = 82397222. Its totient is φ = 82397220.

The previous prime is 82397213. The next prime is 82397233. The reversal of 82397221 is 12279328.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67881121 + 14516100 = 8239^2 + 3810^2 .

It is a cyclic number.

It is not a de Polignac number, because 82397221 - 2³ = 82397213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82397291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41198610 + 41198611.

It is an arithmetic number, because the mean of its divisors is an integer number (41198611).

Almost surely, 2^82397221 is an apocalyptic number.

It is an amenable number.

82397221 is a deficient number, since it is larger than the sum of its proper divisors (1).

82397221 is an equidigital number, since it uses as much as digits as its factorization.

82397221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 34.

The square root of 82397221 is about 9077.2915013235. The cubic root of 82397221 is about 435.1485307731.

The spelling of 82397221 in words is "eighty-two million, three hundred ninety-seven thousand, two hundred twenty-one".