81808110 has 128 divisors (see below), whose sum is σ = 236390400. Its totient is φ = 20062080.

The previous prime is 81808109. The next prime is 81808127. The reversal of 81808110 is 1180818.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 189595 + ... + 190025.

It is an arithmetic number, because the mean of its divisors is an integer number (1846800).

Almost surely, 2^81808110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81808110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118195200).

81808110 is an abundant number, since it is smaller than the sum of its proper divisors (154582290).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81808110 is a wasteful number, since it uses less digits than its factorization.

81808110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503 (or 497 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

The square root of 81808110 is about 9044.7835795004. The cubic root of 81808110 is about 434.1089966705.

Adding to 81808110 its reverse (1180818), we get a palindrome (82988928).

It can be divided in two parts, 81808 and 110, that added together give a palindrome (81918).

The spelling of 81808110 in words is "eighty-one million, eight hundred eight thousand, one hundred ten".