82101861 has 6 divisors (see below), whose sum is σ = 118591590. Its totient is φ = 54734568.

The previous prime is 82101847. The next prime is 82101883. The reversal of 82101861 is 16810128.

It can be written as a sum of positive squares in only one way, i.e., 80460900 + 1640961 = 8970^2 + 1281^2 .

It is not a de Polignac number, because 82101861 - 2⁵ = 82101829 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82101161) 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 5 ways as a sum of consecutive naturals, for example, 4561206 + ... + 4561223.

It is an arithmetic number, because the mean of its divisors is an integer number (19765265).

Almost surely, 2^82101861 is an apocalyptic number.

It is an amenable number.

82101861 is a deficient number, since it is larger than the sum of its proper divisors (36489729).

82101861 is a wasteful number, since it uses less digits than its factorization.

82101861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9122435 (or 9122432 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 82101861 is about 9061.0077254133. The cubic root of 82101861 is about 434.6279656970.

Adding to 82101861 its reverse (16810128), we get a palindrome (98911989).

The spelling of 82101861 in words is "eighty-two million, one hundred one thousand, eight hundred sixty-one".