81045 has 12 divisors (see below), whose sum is σ = 140556. Its totient is φ = 43200.

The previous prime is 81043. The next prime is 81047. The reversal of 81045 is 54018.

It is an interprime number because it is at equal distance from previous prime (81043) and next prime (81047).

It can be written as a sum of positive squares in 2 ways, for example, as 19044 + 62001 = 138^2 + 249^2 .

It is not a de Polignac number, because 81045 - 2¹ = 81043 is a prime.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 856 + ... + 945.

It is an arithmetic number, because the mean of its divisors is an integer number (11713).

2⁸¹⁰⁴⁵ is an apocalyptic number.

It is an amenable number.

81045 is a deficient number, since it is larger than the sum of its proper divisors (59511).

81045 is a wasteful number, since it uses less digits than its factorization.

81045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1812 (or 1809 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 81045 is about 284.6840353796. The cubic root of 81045 is about 43.2754981235.

The spelling of 81045 in words is "eighty-one thousand, forty-five".