82717221 has 8 divisors (see below), whose sum is σ = 110680480. Its totient is φ = 54949392.

The previous prime is 82717171. The next prime is 82717247. The reversal of 82717221 is 12271728.

It is a happy number.

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

It is not a de Polignac number, because 82717221 - 2¹⁵ = 82684453 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82717721) 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 in 7 ways as a sum of consecutive naturals, for example, 47866 + ... + 49563.

It is an arithmetic number, because the mean of its divisors is an integer number (13835060).

Almost surely, 2^82717221 is an apocalyptic number.

It is an amenable number.

82717221 is a deficient number, since it is larger than the sum of its proper divisors (27963259).

82717221 is a wasteful number, since it uses less digits than its factorization.

82717221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97715.

The product of its digits is 3136, while the sum is 30.

The square root of 82717221 is about 9094.9008240882. The cubic root of 82717221 is about 435.7111211708.

Adding to 82717221 its reverse (12271728), we get a palindrome (94988949).

The spelling of 82717221 in words is "eighty-two million, seven hundred seventeen thousand, two hundred twenty-one".