646785747 has 18 divisors (see below), whose sum is σ = 956502612. Its totient is φ = 421151976.

The previous prime is 646785743. The next prime is 646785749. The reversal of 646785747 is 747587646.

646785747 is a `hidden beast` number, since 6 + 4 + 67 + 8 + 574 + 7 = 666.

646785747 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646785747 - 2² = 646785743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646785693 and 646785702.

It is not an unprimeable number, because it can be changed into a prime (646785743) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2793 + ... + 36074.

It is an arithmetic number, because the mean of its divisors is an integer number (53139034).

Almost surely, 2^646785747 is an apocalyptic number.

646785747 is a deficient number, since it is larger than the sum of its proper divisors (309716865).

646785747 is a wasteful number, since it uses less digits than its factorization.

646785747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38959 (or 38913 counting only the distinct ones).

The product of its digits is 7902720, while the sum is 54.

The square root of 646785747 is about 25431.9827579369. The cubic root of 646785747 is about 864.8088931506.

The spelling of 646785747 in words is "six hundred forty-six million, seven hundred eighty-five thousand, seven hundred forty-seven".