21805248259 has 2 divisors, whose sum is σ = 21805248260. Its totient is φ = 21805248258.

The previous prime is 21805248137. The next prime is 21805248313. The reversal of 21805248259 is 95284250812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21805248259 - 2¹⁵ = 21805215491 is a prime.

It is not a weakly prime, because it can be changed into another prime (21805248359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10902624129 + 10902624130.

It is an arithmetic number, because the mean of its divisors is an integer number (10902624130).

Almost surely, 2^21805248259 is an apocalyptic number.

21805248259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21805248259 is an equidigital number, since it uses as much as digits as its factorization.

21805248259 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 460800, while the sum is 46.

The spelling of 21805248259 in words is "twenty-one billion, eight hundred five million, two hundred forty-eight thousand, two hundred fifty-nine".