21078179 has 2 divisors, whose sum is σ = 21078180. Its totient is φ = 21078178.

The previous prime is 21078149. The next prime is 21078191. The reversal of 21078179 is 97187012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21078179 - 2²⁴ = 4300963 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21078119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10539089 + 10539090.

It is an arithmetic number, because the mean of its divisors is an integer number (10539090).

Almost surely, 2^21078179 is an apocalyptic number.

21078179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21078179 is an equidigital number, since it uses as much as digits as its factorization.

21078179 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 21078179 is about 4591.0977990019. The cubic root of 21078179 is about 276.2343586347.

The spelling of 21078179 in words is "twenty-one million, seventy-eight thousand, one hundred seventy-nine".