643248985 has 8 divisors (see below), whose sum is σ = 772090560. Its totient is φ = 514471344.

The previous prime is 643248973. The next prime is 643248989. The reversal of 643248985 is 589842346.

643248985 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643248985 - 2⁵ = 643248953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643248989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9996 + ... + 37234.

It is an arithmetic number, because the mean of its divisors is an integer number (96511320).

Almost surely, 2^643248985 is an apocalyptic number.

It is an amenable number.

643248985 is a deficient number, since it is larger than the sum of its proper divisors (128841575).

643248985 is a wasteful number, since it uses less digits than its factorization.

643248985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31967.

The product of its digits is 1658880, while the sum is 49.

The square root of 643248985 is about 25362.3536959802. The cubic root of 643248985 is about 863.2296915316.

The spelling of 643248985 in words is "six hundred forty-three million, two hundred forty-eight thousand, nine hundred eighty-five".