20638853 has 2 divisors, whose sum is σ = 20638854. Its totient is φ = 20638852.

The previous prime is 20638819. The next prime is 20638861. The reversal of 20638853 is 35883602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20638849 + 4 = 4543^2 + 2^2 .

It is a cyclic number.

It is not a de Polignac number, because 20638853 - 2⁶ = 20638789 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20632853) 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, 10319426 + 10319427.

It is an arithmetic number, because the mean of its divisors is an integer number (10319427).

Almost surely, 2^20638853 is an apocalyptic number.

It is an amenable number.

20638853 is a deficient number, since it is larger than the sum of its proper divisors (1).

20638853 is an equidigital number, since it uses as much as digits as its factorization.

20638853 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 20638853 is about 4543.0004402377. Note that the first 3 decimals coincide. The cubic root of 20638853 is about 274.3017126886.

The spelling of 20638853 in words is "twenty million, six hundred thirty-eight thousand, eight hundred fifty-three".