21366179 has 2 divisors, whose sum is σ = 21366180. Its totient is φ = 21366178.

The previous prime is 21366173. The next prime is 21366181. The reversal of 21366179 is 97166312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21366179 is a prime.

It is a Sophie Germain prime.

Together with 21366181, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21366173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10683089 + 10683090.

It is an arithmetic number, because the mean of its divisors is an integer number (10683090).

Almost surely, 2^21366179 is an apocalyptic number.

21366179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21366179 is an equidigital number, since it uses as much as digits as its factorization.

21366179 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 35.

The square root of 21366179 is about 4622.3564336819. The cubic root of 21366179 is about 277.4867737115.

The spelling of 21366179 in words is "twenty-one million, three hundred sixty-six thousand, one hundred seventy-nine".