21106307647 has 2 divisors, whose sum is σ = 21106307648. Its totient is φ = 21106307646.

The previous prime is 21106307557. The next prime is 21106307659. The reversal of 21106307647 is 74670360112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21106307647 - 2¹⁵ = 21106274879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21106307147) 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, 10553153823 + 10553153824.

It is an arithmetic number, because the mean of its divisors is an integer number (10553153824).

Almost surely, 2^21106307647 is an apocalyptic number.

21106307647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21106307647 is an equidigital number, since it uses as much as digits as its factorization.

21106307647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42336, while the sum is 37.

Adding to 21106307647 its reverse (74670360112), we get a palindrome (95776667759).

The spelling of 21106307647 in words is "twenty-one billion, one hundred six million, three hundred seven thousand, six hundred forty-seven".