643522516 has 24 divisors (see below), whose sum is σ = 1386049280. Its totient is φ = 254580192.

The previous prime is 643522501. The next prime is 643522519. The reversal of 643522516 is 615225346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643522519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 883596 + ... + 884323.

Almost surely, 2^643522516 is an apocalyptic number.

It is an amenable number.

643522516 is an abundant number, since it is smaller than the sum of its proper divisors (742526764).

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

643522516 is a wasteful number, since it uses less digits than its factorization.

643522516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767943 (or 1767941 counting only the distinct ones).

The product of its digits is 43200, while the sum is 34.

The square root of 643522516 is about 25367.7455837132. The cubic root of 643522516 is about 863.3520322454.

The spelling of 643522516 in words is "six hundred forty-three million, five hundred twenty-two thousand, five hundred sixteen".