81373 has 2 divisors, whose sum is σ = 81374. Its totient is φ = 81372.

The previous prime is 81371. The next prime is 81401. The reversal of 81373 is 37318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79524 + 1849 = 282^2 + 43^2 .

81373 is a truncatable prime.

It is a cyclic number.

It is not a de Polignac number, because 81373 - 2¹ = 81371 is a prime.

Together with 81371, it forms a pair of twin primes.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40686 + 40687.

It is an arithmetic number, because the mean of its divisors is an integer number (40687).

2⁸¹³⁷³ is an apocalyptic number.

It is an amenable number.

81373 is a deficient number, since it is larger than the sum of its proper divisors (1).

81373 is an equidigital number, since it uses as much as digits as its factorization.

81373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 22.

The square root of 81373 is about 285.2595309538. The cubic root of 81373 is about 43.3338001265. Note that the first 3 decimals are identical.

It can be divided in two parts, 81 and 373, that added together give a palindrome (454).

The spelling of 81373 in words is "eighty-one thousand, three hundred seventy-three".