81854 has 4 divisors (see below), whose sum is σ = 122784. Its totient is φ = 40926.

The previous prime is 81853. The next prime is 81869. The reversal of 81854 is 45818.

It is a semiprime because it is the product of two primes.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81853) by changing a digit.

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 as a sum of consecutive naturals, namely, 20462 + ... + 20465.

It is an arithmetic number, because the mean of its divisors is an integer number (30696).

2⁸¹⁸⁵⁴ is an apocalyptic number.

81854 is a deficient number, since it is larger than the sum of its proper divisors (40930).

81854 is a wasteful number, since it uses less digits than its factorization.

81854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40929.

The product of its digits is 1280, while the sum is 26.

The square root of 81854 is about 286.1013806328. The cubic root of 81854 is about 43.4190152186.

The spelling of 81854 in words is "eighty-one thousand, eight hundred fifty-four".