643968052 has 48 divisors (see below), whose sum is σ = 1389122560. Its totient is φ = 254368512.

The previous prime is 643968047. The next prime is 643968077. The reversal of 643968052 is 250869346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 410173 + ... + 411739.

Almost surely, 2^643968052 is an apocalyptic number.

It is an amenable number.

643968052 is an abundant number, since it is smaller than the sum of its proper divisors (745154508).

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

643968052 is a wasteful number, since it uses less digits than its factorization.

643968052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2720 (or 2718 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 43.

The square root of 643968052 is about 25376.5256093107. The cubic root of 643968052 is about 863.5512304942.

The spelling of 643968052 in words is "six hundred forty-three million, nine hundred sixty-eight thousand, fifty-two".