21706121163 has 6 divisors (see below), whose sum is σ = 28941835132. Its totient is φ = 14470577320.

The previous prime is 21706121161. The next prime is 21706121273. The reversal of 21706121163 is 36112160712.

It is not a de Polignac number, because 21706121163 - 2¹ = 21706121161 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21706121163.

It is not an unprimeable number, because it can be changed into a prime (21706121161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 212653 + ... + 297713.

Almost surely, 2^21706121163 is an apocalyptic number.

21706121163 is a deficient number, since it is larger than the sum of its proper divisors (7235713969).

21706121163 is an frugal number, since it uses more digits than its factorization.

21706121163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170125 (or 85064 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

Adding to 21706121163 its reverse (36112160712), we get a palindrome (57818281875).

The spelling of 21706121163 in words is "twenty-one billion, seven hundred six million, one hundred twenty-one thousand, one hundred sixty-three".