643068737440 has 36 divisors (see below), whose sum is σ = 1519273856646. Its totient is φ = 257223437568.

The previous prime is 643068737393. The next prime is 643068737453. The reversal of 643068737440 is 44737860346.

643068737440 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 3 ways, for example, as 443220399504 + 199848337936 = 665748^2 + 447044^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10111822 + ... + 10175218.

Almost surely, 2^643068737440 is an apocalyptic number.

It is an amenable number.

643068737440 is an abundant number, since it is smaller than the sum of its proper divisors (876205119206).

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

643068737440 is an frugal number, since it uses more digits than its factorization.

643068737440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126809 (or 63404 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 52.

The spelling of 643068737440 in words is "six hundred forty-three billion, sixty-eight million, seven hundred thirty-seven thousand, four hundred forty".