81032109 has 16 divisors (see below), whose sum is σ = 114547200. Its totient is φ = 50863680.

The previous prime is 81032069. The next prime is 81032123. The reversal of 81032109 is 90123018.

It is not a de Polignac number, because 81032109 - 2¹⁶ = 80966573 is a prime.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81032129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8334 + ... + 15215.

It is an arithmetic number, because the mean of its divisors is an integer number (7159200).

Almost surely, 2^81032109 is an apocalyptic number.

It is an amenable number.

81032109 is a deficient number, since it is larger than the sum of its proper divisors (33515091).

81032109 is a wasteful number, since it uses less digits than its factorization.

81032109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23620.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 81032109 is about 9001.7836565872. The cubic root of 81032109 is about 432.7320353807.

Subtracting 81032109 from its reverse (90123018), we obtain a palindrome (9090909).

The spelling of 81032109 in words is "eighty-one million, thirty-two thousand, one hundred nine".