643797925 has 36 divisors (see below), whose sum is σ = 835327488. Its totient is φ = 492156000.

The previous prime is 643797923. The next prime is 643797953. The reversal of 643797925 is 529797346.

It is not a de Polignac number, because 643797925 - 2¹ = 643797923 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643797923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3051070 + ... + 3051280.

Almost surely, 2^643797925 is an apocalyptic number.

It is an amenable number.

643797925 is a deficient number, since it is larger than the sum of its proper divisors (191529563).

643797925 is a wasteful number, since it uses less digits than its factorization.

643797925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410 (or 374 counting only the distinct ones).

The product of its digits is 2857680, while the sum is 52.

The square root of 643797925 is about 25373.1733332668. The cubic root of 643797925 is about 863.4751779017.

The spelling of 643797925 in words is "six hundred forty-three million, seven hundred ninety-seven thousand, nine hundred twenty-five".