810000081 has 20 divisors (see below), whose sum is σ = 1320001584. Its totient is φ = 490908600.

The previous prime is 810000049. The next prime is 810000083. The reversal of 810000081 is 180000018.

It is a happy number.

810000081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 810000081 - 2⁵ = 810000049 is a prime.

It is a super-2 number, since 2×810000081² = 1312200262440013122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (810000083) 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, 453655 + ... + 455436.

Almost surely, 2^810000081 is an apocalyptic number.

810000081 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

810000081 is a deficient number, since it is larger than the sum of its proper divisors (510001503).

810000081 is a wasteful number, since it uses less digits than its factorization.

810000081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909114 (or 909105 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 810000081 is about 28460.5003645403. The cubic root of 810000081 is about 932.1697828585.

Adding to 810000081 its reverse (180000018), we get a palindrome (990000099).

The spelling of 810000081 in words is "eight hundred ten million, eighty-one", and thus it is an aban number.