21705299267 has 2 divisors, whose sum is σ = 21705299268. Its totient is φ = 21705299266.

The previous prime is 21705299149. The next prime is 21705299279. The reversal of 21705299267 is 76299250712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21705299267 - 2¹⁴ = 21705282883 is a prime.

It is a super-2 number, since 2×21705299267² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21705290267) 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, 10852649633 + 10852649634.

It is an arithmetic number, because the mean of its divisors is an integer number (10852649634).

Almost surely, 2^21705299267 is an apocalyptic number.

21705299267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21705299267 is an equidigital number, since it uses as much as digits as its factorization.

21705299267 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 952560, while the sum is 50.

The spelling of 21705299267 in words is "twenty-one billion, seven hundred five million, two hundred ninety-nine thousand, two hundred sixty-seven".