81910 has 8 divisors (see below), whose sum is σ = 147456. Its totient is φ = 32760.

The previous prime is 81901. The next prime is 81919. The reversal of 81910 is 1918.

It is an interprime number because it is at equal distance from previous prime (81901) and next prime (81919).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81919) by changing a digit.

81910 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 4086 + ... + 4105.

It is an arithmetic number, because the mean of its divisors is an integer number (18432).

2⁸¹⁹¹⁰ is an apocalyptic number.

81910 is a deficient number, since it is larger than the sum of its proper divisors (65546).

81910 is a wasteful number, since it uses less digits than its factorization.

81910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8198.

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

The square root of 81910 is about 286.1992313057. The cubic root of 81910 is about 43.4289145946.

The spelling of 81910 in words is "eighty-one thousand, nine hundred ten".