643829967 has 24 divisors (see below), whose sum is σ = 1074200400. Its totient is φ = 367246080.

The previous prime is 643829941. The next prime is 643829969. The reversal of 643829967 is 769928346.

It is a happy number.

It is not a de Polignac number, because 643829967 - 2¹⁰ = 643828943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643829969) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 189592 + ... + 192957.

It is an arithmetic number, because the mean of its divisors is an integer number (44758350).

Almost surely, 2^643829967 is an apocalyptic number.

643829967 is a deficient number, since it is larger than the sum of its proper divisors (430370433).

643829967 is a wasteful number, since it uses less digits than its factorization.

643829967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382583 (or 382580 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 54.

The square root of 643829967 is about 25373.8047403223. The cubic root of 643829967 is about 863.4895027965.

The spelling of 643829967 in words is "six hundred forty-three million, eight hundred twenty-nine thousand, nine hundred sixty-seven".