643004004520 has 128 divisors (see below), whose sum is σ = 1505481811200. Its totient is φ = 246870163456.

The previous prime is 643004004427. The next prime is 643004004611. The reversal of 643004004520 is 25400400346.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 233563464 + ... + 233566216.

It is an arithmetic number, because the mean of its divisors is an integer number (11761576650).

Almost surely, 2^643004004520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643004004520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (752740905600).

643004004520 is an abundant number, since it is smaller than the sum of its proper divisors (862477806680).

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

643004004520 is a wasteful number, since it uses less digits than its factorization.

643004004520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3907 (or 3903 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 643004004520 its reverse (25400400346), we get a palindrome (668404404866).

The spelling of 643004004520 in words is "six hundred forty-three billion, four million, four thousand, five hundred twenty".