643829338 has 8 divisors (see below), whose sum is σ = 1022552532. Its totient is φ = 302978496.

The previous prime is 643829323. The next prime is 643829339. The reversal of 643829338 is 833928346.

It can be written as a sum of positive squares in 2 ways, for example, as 642774609 + 1054729 = 25353^2 + 1027^2 .

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

It is not an unprimeable number, because it can be changed into a prime (643829339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9468045 + ... + 9468112.

Almost surely, 2^643829338 is an apocalyptic number.

643829338 is a deficient number, since it is larger than the sum of its proper divisors (378723194).

643829338 is a wasteful number, since it uses less digits than its factorization.

643829338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18936176.

The product of its digits is 746496, while the sum is 46.

The square root of 643829338 is about 25373.7923456467. The cubic root of 643829338 is about 863.4892215964.

The spelling of 643829338 in words is "six hundred forty-three million, eight hundred twenty-nine thousand, three hundred thirty-eight".