646787646 has 32 divisors (see below), whose sum is σ = 1499800320. Its totient is φ = 206221752.

The previous prime is 646787597. The next prime is 646787651.

It is a happy number.

646787646 is nontrivially palindromic in base 10.

646787646 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 646787592 and 646787601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259140 + ... + 261623.

It is an arithmetic number, because the mean of its divisors is an integer number (46868760).

Almost surely, 2^646787646 is an apocalyptic number.

646787646 is an abundant number, since it is smaller than the sum of its proper divisors (853012674).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646787646 is a wasteful number, since it uses less digits than its factorization.

646787646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520797 (or 520791 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 54.

The square root of 646787646 is about 25432.0200927885. The cubic root of 646787646 is about 864.8097395259.

The spelling of 646787646 in words is "six hundred forty-six million, seven hundred eighty-seven thousand, six hundred forty-six".