21705258683 has 4 divisors (see below), whose sum is σ = 21710226528. Its totient is φ = 21700290840.

The previous prime is 21705258671. The next prime is 21705258697. The reversal of 21705258683 is 38685250712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21705258683 - 2⁴ = 21705258667 is a prime.

It is a super-2 number, since 2×21705258683² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21705258643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2477363 + ... + 2486108.

It is an arithmetic number, because the mean of its divisors is an integer number (5427556632).

Almost surely, 2^21705258683 is an apocalyptic number.

21705258683 is a deficient number, since it is larger than the sum of its proper divisors (4967845).

21705258683 is an equidigital number, since it uses as much as digits as its factorization.

21705258683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4967844.

The product of its (nonzero) digits is 806400, while the sum is 47.

The spelling of 21705258683 in words is "twenty-one billion, seven hundred five million, two hundred fifty-eight thousand, six hundred eighty-three".