21179 has 2 divisors, whose sum is σ = 21180. Its totient is φ = 21178.

The previous prime is 21169. The next prime is 21187. The reversal of 21179 is 97112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21179 - 2⁴ = 21163 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21179.

It is not a weakly prime, because it can be changed into another prime (21139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10589 + 10590.

It is an arithmetic number, because the mean of its divisors is an integer number (10590).

2²¹¹⁷⁹ is an apocalyptic number.

21179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21179 is an equidigital number, since it uses as much as digits as its factorization.

21179 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 126, while the sum is 20.

The square root of 21179 is about 145.5300656222. The cubic root of 21179 is about 27.6674085703.

The spelling of 21179 in words is "twenty-one thousand, one hundred seventy-nine".