2006643787 has 2 divisors, whose sum is σ = 2006643788. Its totient is φ = 2006643786.

The previous prime is 2006643703. The next prime is 2006643799. The reversal of 2006643787 is 7873466002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2006643787 is a prime.

It is not a weakly prime, because it can be changed into another prime (2006643887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1003321893 + 1003321894.

It is an arithmetic number, because the mean of its divisors is an integer number (1003321894).

Almost surely, 2^2006643787 is an apocalyptic number.

2006643787 is a deficient number, since it is larger than the sum of its proper divisors (1).

2006643787 is an equidigital number, since it uses as much as digits as its factorization.

2006643787 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 338688, while the sum is 43.

The square root of 2006643787 is about 44795.5777616496. The cubic root of 2006643787 is about 1261.3146157883.

The spelling of 2006643787 in words is "two billion, six million, six hundred forty-three thousand, seven hundred eighty-seven".