810109 has 2 divisors, whose sum is σ = 810110. Its totient is φ = 810108.

The previous prime is 810091. The next prime is 810137. The reversal of 810109 is 901018.

Together with previous prime (810091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 632025 + 178084 = 795^2 + 422^2 .

It is a cyclic number.

It is not a de Polignac number, because 810109 - 2⁷ = 809981 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405054 + 405055.

It is an arithmetic number, because the mean of its divisors is an integer number (405055).

2⁸¹⁰¹⁰⁹ is an apocalyptic number.

It is an amenable number.

810109 is a deficient number, since it is larger than the sum of its proper divisors (1).

810109 is an equidigital number, since it uses as much as digits as its factorization.

810109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 810109 is about 900.0605535185. The cubic root of 810109 is about 93.2211563286.

Subtracting 810109 from its reverse (901018), we obtain a palindrome (90909).

It can be divided in two parts, 810 and 109, that added together give a palindrome (919).

The spelling of 810109 in words is "eight hundred ten thousand, one hundred nine".