643129967 has 8 divisors (see below), whose sum is σ = 661875792. Its totient is φ = 624456000.

The previous prime is 643129961. The next prime is 643129969. The reversal of 643129967 is 769921346.

It is a happy number.

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 643129967 - 2⁴ = 643129951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643129961) 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, 467 + ... + 35867.

It is an arithmetic number, because the mean of its divisors is an integer number (82734474).

Almost surely, 2^643129967 is an apocalyptic number.

643129967 is a deficient number, since it is larger than the sum of its proper divisors (18745825).

643129967 is a wasteful number, since it uses less digits than its factorization.

643129967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35929.

The product of its digits is 489888, while the sum is 47.

The square root of 643129967 is about 25360.0072358034. The cubic root of 643129967 is about 863.1764481733.

The spelling of 643129967 in words is "six hundred forty-three million, one hundred twenty-nine thousand, nine hundred sixty-seven".