643946700 has 36 divisors (see below), whose sum is σ = 1863153320. Its totient is φ = 171719040.

The previous prime is 643946669. The next prime is 643946707. The reversal of 643946700 is 7649346.

It is not an unprimeable number, because it can be changed into a prime (643946707) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1072945 + ... + 1073544.

Almost surely, 2^643946700 is an apocalyptic number.

643946700 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643946700 is an abundant number, since it is smaller than the sum of its proper divisors (1219206620).

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

643946700 is a wasteful number, since it uses less digits than its factorization.

643946700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2146506 (or 2146499 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 39.

The square root of 643946700 is about 25376.1049020530. The cubic root of 643946700 is about 863.5416861544.

The spelling of 643946700 in words is "six hundred forty-three million, nine hundred forty-six thousand, seven hundred".