82111561540849 has 27 divisors (see below), whose sum is σ = 85536371204193. Its totient is φ = 78820635661824.

The previous prime is 82111561540751. The next prime is 82111561540903. The reversal of 82111561540849 is 94804516511128.

The square root of 82111561540849 is 9061543.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 4883812704225 + 77227748836624 = 2209935^2 + 8787932^2 .

It is not a de Polignac number, because 82111561540849 - 2⁷ = 82111561540721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 82111561540849.

It is not an unprimeable number, because it can be changed into a prime (82111561540649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 50717455362 + ... + 50717456980.

Almost surely, 2^{82111561540849} is an apocalyptic number.

82111561540849 is the 9061543-rd square number.

82111561540849 is the 4530772-nd centered octagonal number.

It is an amenable number.

82111561540849 is a deficient number, since it is larger than the sum of its proper divisors (3424809663344).

82111561540849 is an frugal number, since it uses more digits than its factorization.

82111561540849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3682 (or 1841 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 55.

The spelling of 82111561540849 in words is "eighty-two trillion, one hundred eleven billion, five hundred sixty-one million, five hundred forty thousand, eight hundred forty-nine".