643521346 has 8 divisors (see below), whose sum is σ = 1039534524. Its totient is φ = 297009840.

The previous prime is 643521331. The next prime is 643521371. The reversal of 643521346 is 643125346.

643521346 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 619462321 + 24059025 = 24889^2 + 4905^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12375385 + ... + 12375436.

Almost surely, 2^643521346 is an apocalyptic number.

643521346 is a deficient number, since it is larger than the sum of its proper divisors (396013178).

643521346 is a wasteful number, since it uses less digits than its factorization.

643521346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24750836.

The product of its digits is 51840, while the sum is 34.

The square root of 643521346 is about 25367.7225229227. The cubic root of 643521346 is about 863.3515090197.

The spelling of 643521346 in words is "six hundred forty-three million, five hundred twenty-one thousand, three hundred forty-six".