79681 has 4 divisors (see below), whose sum is σ = 91072. Its totient is φ = 68292.

The previous prime is 79669. The next prime is 79687. The reversal of 79681 is 18697.

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 an emirpimes, since its reverse is a distinct semiprime: 18697 = 7 ⋅2671.

It is a de Polignac number, because none of the positive numbers 2^k-79681 is a prime.

It is a super-2 number, since 2×79681² = 12698123522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79687) 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, 5685 + ... + 5698.

It is an arithmetic number, because the mean of its divisors is an integer number (22768).

2⁷⁹⁶⁸¹ is an apocalyptic number.

It is an amenable number.

79681 is a deficient number, since it is larger than the sum of its proper divisors (11391).

79681 is a wasteful number, since it uses less digits than its factorization.

79681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11390.

The product of its digits is 3024, while the sum is 31.

The square root of 79681 is about 282.2782315376. The cubic root of 79681 is about 43.0313454519.

The spelling of 79681 in words is "seventy-nine thousand, six hundred eighty-one".