79942 has 4 divisors (see below), whose sum is σ = 119916. Its totient is φ = 39970.

The previous prime is 79939. The next prime is 79943. The reversal of 79942 is 24997.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24997 = 7 ⋅3571.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19984 + ... + 19987.

It is an arithmetic number, because the mean of its divisors is an integer number (29979).

2⁷⁹⁹⁴² is an apocalyptic number.

79942 is a deficient number, since it is larger than the sum of its proper divisors (39974).

79942 is a wasteful number, since it uses less digits than its factorization.

79942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39973.

The product of its digits is 4536, while the sum is 31.

The square root of 79942 is about 282.7401634010. The cubic root of 79942 is about 43.0782781821.

Subtracting from 79942 its reverse (24997), we obtain a palindrome (54945).

It can be divided in two parts, 799 and 42, that added together give a square (841 = 29²).

The spelling of 79942 in words is "seventy-nine thousand, nine hundred forty-two".