20841647 has 2 divisors, whose sum is σ = 20841648. Its totient is φ = 20841646.

The previous prime is 20841637. The next prime is 20841649. The reversal of 20841647 is 74614802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20841647 - 2⁴ = 20841631 is a prime.

Together with 20841649, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20841649) 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, 10420823 + 10420824.

It is an arithmetic number, because the mean of its divisors is an integer number (10420824).

Almost surely, 2^20841647 is an apocalyptic number.

20841647 is a deficient number, since it is larger than the sum of its proper divisors (1).

20841647 is an equidigital number, since it uses as much as digits as its factorization.

20841647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 20841647 is about 4565.2652715916. The cubic root of 20841647 is about 275.1972007036.

The spelling of 20841647 in words is "twenty million, eight hundred forty-one thousand, six hundred forty-seven".