181979 has 4 divisors (see below), whose sum is σ = 207984. Its totient is φ = 155976.

The previous prime is 181967. The next prime is 181981. The reversal of 181979 is 979181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979181 = 7 ⋅139883.

It is a cyclic number.

It is not a de Polignac number, because 181979 - 2¹² = 177883 is a prime.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (181919) 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, 12992 + ... + 13005.

It is an arithmetic number, because the mean of its divisors is an integer number (51996).

2¹⁸¹⁹⁷⁹ is an apocalyptic number.

181979 is a deficient number, since it is larger than the sum of its proper divisors (26005).

181979 is an equidigital number, since it uses as much as digits as its factorization.

181979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26004.

The product of its digits is 4536, while the sum is 35.

The square root of 181979 is about 426.5899670644. The cubic root of 181979 is about 56.6683313621.

The spelling of 181979 in words is "one hundred eighty-one thousand, nine hundred seventy-nine".