79966 has 4 divisors (see below), whose sum is σ = 119952. Its totient is φ = 39982.

The previous prime is 79943. The next prime is 79967. The reversal of 79966 is 66997.

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

It is a super-2 number, since 2×79966² = 12789122312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79967) by changing a digit.

79966 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19990 + ... + 19993.

It is an arithmetic number, because the mean of its divisors is an integer number (29988).

2⁷⁹⁹⁶⁶ is an apocalyptic number.

79966 is a deficient number, since it is larger than the sum of its proper divisors (39986).

79966 is a wasteful number, since it uses less digits than its factorization.

79966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39985.

The product of its digits is 20412, while the sum is 37.

The square root of 79966 is about 282.7826020108. The cubic root of 79966 is about 43.0825887040.

The spelling of 79966 in words is "seventy-nine thousand, nine hundred sixty-six".