646463999 has 6 divisors (see below), whose sum is σ = 682279560. Its totient is φ = 612439236.

The previous prime is 646463989. The next prime is 646464011. The reversal of 646463999 is 999364646.

It is a happy number.

646463999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-646463999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646463959) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 895019 + ... + 895740.

It is an arithmetic number, because the mean of its divisors is an integer number (113713260).

Almost surely, 2^646463999 is an apocalyptic number.

646463999 is a deficient number, since it is larger than the sum of its proper divisors (35815561).

646463999 is a wasteful number, since it uses less digits than its factorization.

646463999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1790797 (or 1790778 counting only the distinct ones).

The product of its digits is 7558272, while the sum is 56.

The square root of 646463999 is about 25425.6563140463. The cubic root of 646463999 is about 864.6654676628.

The spelling of 646463999 in words is "six hundred forty-six million, four hundred sixty-three thousand, nine hundred ninety-nine".