646006993 has 2 divisors, whose sum is σ = 646006994. Its totient is φ = 646006992.

The previous prime is 646006967. The next prime is 646007041. The reversal of 646006993 is 399600646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 360126529 + 285880464 = 18977^2 + 16908^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646006993 is a prime.

646006993 is a modest number, since divided by 6993 gives 646 as remainder.

It is equal to p_33596584 and since 646006993 and 33596584 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (646006903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323003496 + 323003497.

It is an arithmetic number, because the mean of its divisors is an integer number (323003497).

Almost surely, 2^646006993 is an apocalyptic number.

It is an amenable number.

646006993 is a deficient number, since it is larger than the sum of its proper divisors (1).

646006993 is an equidigital number, since it uses as much as digits as its factorization.

646006993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 43.

The square root of 646006993 is about 25416.6676218579. The cubic root of 646006993 is about 864.4616664404.

The spelling of 646006993 in words is "six hundred forty-six million, six thousand, nine hundred ninety-three".