82601221 has 2 divisors, whose sum is σ = 82601222. Its totient is φ = 82601220.

The previous prime is 82601219. The next prime is 82601261. The reversal of 82601221 is 12210628.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62252100 + 20349121 = 7890^2 + 4511^2 .

It is a cyclic number.

It is not a de Polignac number, because 82601221 - 2¹ = 82601219 is a prime.

Together with 82601219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 82601192 and 82601201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82601261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41300610 + 41300611.

It is an arithmetic number, because the mean of its divisors is an integer number (41300611).

Almost surely, 2^82601221 is an apocalyptic number.

It is an amenable number.

82601221 is a deficient number, since it is larger than the sum of its proper divisors (1).

82601221 is an equidigital number, since it uses as much as digits as its factorization.

82601221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 82601221 is about 9088.5213868924. The cubic root of 82601221 is about 435.5073500807.

Adding to 82601221 its reverse (12210628), we get a palindrome (94811849).

The spelling of 82601221 in words is "eighty-two million, six hundred one thousand, two hundred twenty-one".