21920179 has 2 divisors, whose sum is σ = 21920180. Its totient is φ = 21920178.

The previous prime is 21920177. The next prime is 21920203. The reversal of 21920179 is 97102912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21920179 - 2¹ = 21920177 is a prime.

Together with 21920177, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21920179.

It is not a weakly prime, because it can be changed into another prime (21920177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10960089 + 10960090.

It is an arithmetic number, because the mean of its divisors is an integer number (10960090).

Almost surely, 2^21920179 is an apocalyptic number.

21920179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21920179 is an equidigital number, since it uses as much as digits as its factorization.

21920179 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 21920179 is about 4681.8990805014. The cubic root of 21920179 is about 279.8646412075.

The spelling of 21920179 in words is "twenty-one million, nine hundred twenty thousand, one hundred seventy-nine".