82642221 has 8 divisors (see below), whose sum is σ = 122432960. Its totient is φ = 55094796.

The previous prime is 82642213. The next prime is 82642223. The reversal of 82642221 is 12224628.

It is a happy number.

It is not a de Polignac number, because 82642221 - 2³ = 82642213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 3060823 = 82642221 / (8 + 2 + 6 + 4 + 2 + 2 + 2 + 1).

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 (82642223) 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, 1530385 + ... + 1530438.

It is an arithmetic number, because the mean of its divisors is an integer number (15304120).

Almost surely, 2^82642221 is an apocalyptic number.

It is an amenable number.

82642221 is a deficient number, since it is larger than the sum of its proper divisors (39790739).

82642221 is a wasteful number, since it uses less digits than its factorization.

82642221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3060832 (or 3060826 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 82642221 is about 9090.7766994905. The cubic root of 82642221 is about 435.5793944066.

Adding to 82642221 its reverse (12224628), we get a palindrome (94866849).

The spelling of 82642221 in words is "eighty-two million, six hundred forty-two thousand, two hundred twenty-one".