8100009 has 6 divisors (see below), whose sum is σ = 11700026. Its totient is φ = 5400000.

The previous prime is 8099999. The next prime is 8100073. The reversal of 8100009 is 9000018.

It can be written as a sum of positive squares in only one way, i.e., 7683984 + 416025 = 2772^2 + 645^2 .

It is not a de Polignac number, because 8100009 - 2¹¹ = 8097961 is a prime.

It is a super-2 number, since 2×8100009² = 131220291600162, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8099964 and 8100000.

It is not an unprimeable number, because it can be changed into a prime (8100709) 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, 449992 + ... + 450009.

Almost surely, 2^8100009 is an apocalyptic number.

It is an amenable number.

8100009 is a deficient number, since it is larger than the sum of its proper divisors (3600017).

8100009 is a wasteful number, since it uses less digits than its factorization.

8100009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900007 (or 900004 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 8100009 is about 2846.0514752899. The cubic root of 8100009 is about 200.8299594061.

Subtracting 8100009 from its reverse (9000018), we obtain a palindrome (900009).

It can be divided in two parts, 810000 and 9, that multiplied together give a square (7290000 = 2700²).

The spelling of 8100009 in words is "eight million, one hundred thousand, nine".