643221542552 has 16 divisors (see below), whose sum is σ = 1258476931440. Its totient is φ = 307627694176.

The previous prime is 643221542519. The next prime is 643221542573. The reversal of 643221542552 is 255245122346.

It is a congruent number.

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, 1747884443 + ... + 1747884810.

It is an arithmetic number, because the mean of its divisors is an integer number (78654808215).

Almost surely, 2^643221542552 is an apocalyptic number.

It is an amenable number.

643221542552 is a deficient number, since it is larger than the sum of its proper divisors (615255388888).

643221542552 is a wasteful number, since it uses less digits than its factorization.

643221542552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495769282 (or 3495769278 counting only the distinct ones).

The product of its digits is 576000, while the sum is 41.

Adding to 643221542552 its reverse (255245122346), we get a palindrome (898466664898).

The spelling of 643221542552 in words is "six hundred forty-three billion, two hundred twenty-one million, five hundred forty-two thousand, five hundred fifty-two".