21775379 has 2 divisors, whose sum is σ = 21775380. Its totient is φ = 21775378.

The previous prime is 21775357. The next prime is 21775393. The reversal of 21775379 is 97357712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21775379 - 2⁸ = 21775123 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21775309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10887689 + 10887690.

It is an arithmetic number, because the mean of its divisors is an integer number (10887690).

Almost surely, 2^21775379 is an apocalyptic number.

21775379 is a deficient number, since it is larger than the sum of its proper divisors (1).

21775379 is an equidigital number, since it uses as much as digits as its factorization.

21775379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92610, while the sum is 41.

The square root of 21775379 is about 4666.4096476842. The cubic root of 21775379 is about 279.2470373580.

The spelling of 21775379 in words is "twenty-one million, seven hundred seventy-five thousand, three hundred seventy-nine".