809197665111 has 20 divisors (see below), whose sum is σ = 1318692492744. Its totient is φ = 490422826800.

The previous prime is 809197665091. The next prime is 809197665139. The reversal of 809197665111 is 111566791908.

It is a happy number.

It is not a de Polignac number, because 809197665111 - 2⁶ = 809197665047 is a prime.

It is a super-2 number, since 2×809197665111² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809197665911) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 454094320 + ... + 454096101.

Almost surely, 2^809197665111 is an apocalyptic number.

809197665111 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

809197665111 is a deficient number, since it is larger than the sum of its proper divisors (509494827633).

809197665111 is a wasteful number, since it uses less digits than its factorization.

809197665111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908190444 (or 908190435 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 54.

The spelling of 809197665111 in words is "eight hundred nine billion, one hundred ninety-seven million, six hundred sixty-five thousand, one hundred eleven".