20106643 has 2 divisors, whose sum is σ = 20106644. Its totient is φ = 20106642.

The previous prime is 20106641. The next prime is 20106649. The reversal of 20106643 is 34660102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20106643 - 2¹ = 20106641 is a prime.

Together with 20106641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20106641) 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, 10053321 + 10053322.

It is an arithmetic number, because the mean of its divisors is an integer number (10053322).

Almost surely, 2^20106643 is an apocalyptic number.

20106643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20106643 is an equidigital number, since it uses as much as digits as its factorization.

20106643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20106643 is about 4484.0431532268. The cubic root of 20106643 is about 271.9233627445.

Adding to 20106643 its reverse (34660102), we get a palindrome (54766745).

The spelling of 20106643 in words is "twenty million, one hundred six thousand, six hundred forty-three".