643215326 has 16 divisors (see below), whose sum is σ = 1067123904. Its totient is φ = 288844704.

The previous prime is 643215317. The next prime is 643215347. The reversal of 643215326 is 623512346.

It is a junction number, because it is equal to n+sod(n) for n = 643215292 and 643215301.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333350 + ... + 335273.

It is an arithmetic number, because the mean of its divisors is an integer number (66695244).

Almost surely, 2^643215326 is an apocalyptic number.

643215326 is a deficient number, since it is larger than the sum of its proper divisors (423908578).

643215326 is a wasteful number, since it uses less digits than its factorization.

643215326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668675.

The product of its digits is 25920, while the sum is 32.

The square root of 643215326 is about 25361.6901250686. The cubic root of 643215326 is about 863.2146346585.

The spelling of 643215326 in words is "six hundred forty-three million, two hundred fifteen thousand, three hundred twenty-six".