82100221 has 8 divisors (see below), whose sum is σ = 93893184. Its totient is φ = 70323360.

The previous prime is 82100219. The next prime is 82100237. The reversal of 82100221 is 12200128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 82100221 - 2¹ = 82100219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 82100195 and 82100204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82100261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10326 + ... + 16456.

It is an arithmetic number, because the mean of its divisors is an integer number (11736648).

Almost surely, 2^82100221 is an apocalyptic number.

It is an amenable number.

82100221 is a deficient number, since it is larger than the sum of its proper divisors (11792963).

82100221 is a wasteful number, since it uses less digits than its factorization.

82100221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8051.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 82100221 is about 9060.9172273010. The cubic root of 82100221 is about 434.6250717529.

Adding to 82100221 its reverse (12200128), we get a palindrome (94300349).

The spelling of 82100221 in words is "eighty-two million, one hundred thousand, two hundred twenty-one".