643354326 has 80 divisors (see below), whose sum is σ = 1526603760. Its totient is φ = 201942720.

The previous prime is 643354319. The next prime is 643354337. The reversal of 643354326 is 623453346.

643354326 is a `hidden beast` number, since 64 + 33 + 543 + 26 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 605836 + ... + 606896.

It is an arithmetic number, because the mean of its divisors is an integer number (19082547).

Almost surely, 2^643354326 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643354326, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (763301880).

643354326 is an abundant number, since it is smaller than the sum of its proper divisors (883249434).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643354326 is a wasteful number, since it uses less digits than its factorization.

643354326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291 (or 1282 counting only the distinct ones).

The product of its digits is 155520, while the sum is 36.

The square root of 643354326 is about 25364.4303306816. The cubic root of 643354326 is about 863.2768109300.

The spelling of 643354326 in words is "six hundred forty-three million, three hundred fifty-four thousand, three hundred twenty-six".