643666352 has 30 divisors (see below), whose sum is σ = 1450714068. Its totient is φ = 275856672.

The previous prime is 643666351. The next prime is 643666367. The reversal of 643666352 is 253666346.

It is not an unprimeable number, because it can be changed into a prime (643666351) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 409718 + ... + 411285.

Almost surely, 2^643666352 is an apocalyptic number.

It is an amenable number.

643666352 is an abundant number, since it is smaller than the sum of its proper divisors (807047716).

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

643666352 is a wasteful number, since it uses less digits than its factorization.

643666352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821025 (or 821012 counting only the distinct ones).

The product of its digits is 466560, while the sum is 41.

The square root of 643666352 is about 25370.5804427096. The cubic root of 643666352 is about 863.4163510786.

The spelling of 643666352 in words is "six hundred forty-three million, six hundred sixty-six thousand, three hundred fifty-two".