179981 has 2 divisors, whose sum is σ = 179982. Its totient is φ = 179980.

The previous prime is 179969. The next prime is 179989. The reversal of 179981 is 189971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168100 + 11881 = 410^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 179981 - 2⁶ = 179917 is a prime.

It is a super-2 number, since 2×179981² = 64786320722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (179989) 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 as a sum of consecutive naturals, namely, 89990 + 89991.

It is an arithmetic number, because the mean of its divisors is an integer number (89991).

2¹⁷⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

179981 is a deficient number, since it is larger than the sum of its proper divisors (1).

179981 is an equidigital number, since it uses as much as digits as its factorization.

179981 is an odious number, because the sum of its binary digits is odd.

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

The square root of 179981 is about 424.2416764063. The cubic root of 179981 is about 56.4601750313.

The spelling of 179981 in words is "one hundred seventy-nine thousand, nine hundred eighty-one".