79381 has 4 divisors (see below), whose sum is σ = 80032. Its totient is φ = 78732.

The previous prime is 79379. The next prime is 79393. The reversal of 79381 is 18397.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(79381) divides (79381-1)³.

It is a cyclic number.

It is not a de Polignac number, because 79381 - 2¹ = 79379 is a prime.

It is a super-2 number, since 2×79381² = 12602686322, which contains 22 as substring.

It is a Duffinian number.

79381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81 + ... + 406.

It is an arithmetic number, because the mean of its divisors is an integer number (20008).

2⁷⁹³⁸¹ is an apocalyptic number.

79381 is the 163-rd octagonal number.

It is an amenable number.

79381 is a deficient number, since it is larger than the sum of its proper divisors (651).

79381 is a wasteful number, since it uses less digits than its factorization.

79381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650.

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

The square root of 79381 is about 281.7463398165. The cubic root of 79381 is about 42.9772730090.

The spelling of 79381 in words is "seventy-nine thousand, three hundred eighty-one".