21226379 has 2 divisors, whose sum is σ = 21226380. Its totient is φ = 21226378.

The previous prime is 21226367. The next prime is 21226393. The reversal of 21226379 is 97362212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21226379 - 2²⁴ = 4449163 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21226879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613189 + 10613190.

It is an arithmetic number, because the mean of its divisors is an integer number (10613190).

Almost surely, 2^21226379 is an apocalyptic number.

21226379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226379 is an equidigital number, since it uses as much as digits as its factorization.

21226379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 32.

The square root of 21226379 is about 4607.2094590978. The cubic root of 21226379 is about 276.8802455579.

The spelling of 21226379 in words is "twenty-one million, two hundred twenty-six thousand, three hundred seventy-nine".