81379 has 4 divisors (see below), whose sum is σ = 86184. Its totient is φ = 76576.

The previous prime is 81373. The next prime is 81401. The reversal of 81379 is 97318.

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

It is a cyclic number.

It is not a de Polignac number, because 81379 - 2³ = 81371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2377 + ... + 2410.

It is an arithmetic number, because the mean of its divisors is an integer number (21546).

2⁸¹³⁷⁹ is an apocalyptic number.

81379 is a deficient number, since it is larger than the sum of its proper divisors (4805).

81379 is a wasteful number, since it uses less digits than its factorization.

81379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4804.

The product of its digits is 1512, while the sum is 28.

The square root of 81379 is about 285.2700474989. The cubic root of 81379 is about 43.3348651661.

The spelling of 81379 in words is "eighty-one thousand, three hundred seventy-nine".