20648647 has 2 divisors, whose sum is σ = 20648648. Its totient is φ = 20648646.

The previous prime is 20648599. The next prime is 20648699. The reversal of 20648647 is 74684602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20648647 - 2¹⁹ = 20124359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20640647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10324323 + 10324324.

It is an arithmetic number, because the mean of its divisors is an integer number (10324324).

Almost surely, 2^20648647 is an apocalyptic number.

20648647 is a deficient number, since it is larger than the sum of its proper divisors (1).

20648647 is an equidigital number, since it uses as much as digits as its factorization.

20648647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 37.

The square root of 20648647 is about 4544.0782343617. The cubic root of 20648647 is about 274.3450950434.

The spelling of 20648647 in words is "twenty million, six hundred forty-eight thousand, six hundred forty-seven".