646543625 has 64 divisors (see below), whose sum is σ = 1003871232. Its totient is φ = 404812800.

The previous prime is 646543619. The next prime is 646543633. The reversal of 646543625 is 526345646.

It is a happy number.

It is not a de Polignac number, because 646543625 - 2⁸ = 646543369 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1285124 + ... + 1285626.

It is an arithmetic number, because the mean of its divisors is an integer number (15685488).

Almost surely, 2^646543625 is an apocalyptic number.

646543625 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

646543625 is a deficient number, since it is larger than the sum of its proper divisors (357327607).

646543625 is a wasteful number, since it uses less digits than its factorization.

646543625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651 (or 641 counting only the distinct ones).

The product of its digits is 518400, while the sum is 41.

The square root of 646543625 is about 25427.2221251162. Note that the first 3 decimals coincide. The cubic root of 646543625 is about 864.7009669461.

The spelling of 646543625 in words is "six hundred forty-six million, five hundred forty-three thousand, six hundred twenty-five".