21706430227 has 4 divisors (see below), whose sum is σ = 22168269216. Its totient is φ = 21244591240.

The previous prime is 21706430201. The next prime is 21706430231. The reversal of 21706430227 is 72203460712.

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 21706430227 - 2¹⁵ = 21706397459 is a prime.

It is a super-2 number, since 2×21706430227² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21706430192 and 21706430201.

It is not an unprimeable number, because it can be changed into a prime (21706430267) 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 3 ways as a sum of consecutive naturals, for example, 230919424 + ... + 230919517.

It is an arithmetic number, because the mean of its divisors is an integer number (5542067304).

Almost surely, 2^21706430227 is an apocalyptic number.

21706430227 is a deficient number, since it is larger than the sum of its proper divisors (461838989).

21706430227 is an equidigital number, since it uses as much as digits as its factorization.

21706430227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461838988.

The product of its (nonzero) digits is 28224, while the sum is 34.

Adding to 21706430227 its reverse (72203460712), we get a palindrome (93909890939).

The spelling of 21706430227 in words is "twenty-one billion, seven hundred six million, four hundred thirty thousand, two hundred twenty-seven".