21824879 has 2 divisors, whose sum is σ = 21824880. Its totient is φ = 21824878.

The previous prime is 21824851. The next prime is 21824893. The reversal of 21824879 is 97842812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21824879 - 2²⁴ = 5047663 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21824809) 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, 10912439 + 10912440.

It is an arithmetic number, because the mean of its divisors is an integer number (10912440).

Almost surely, 2^21824879 is an apocalyptic number.

21824879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21824879 is an equidigital number, since it uses as much as digits as its factorization.

21824879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 41.

The square root of 21824879 is about 4671.7105004484. The cubic root of 21824879 is about 279.4584729059.

The spelling of 21824879 in words is "twenty-one million, eight hundred twenty-four thousand, eight hundred seventy-nine".