643550243576 has 16 divisors (see below), whose sum is σ = 1206971571600. Its totient is φ = 321691157824.

The previous prime is 643550243449. The next prime is 643550243603. The reversal of 643550243576 is 675342055346.

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, 10462916 + ... + 10524243.

It is an arithmetic number, because the mean of its divisors is an integer number (75435723225).

Almost surely, 2^643550243576 is an apocalyptic number.

It is an amenable number.

643550243576 is a deficient number, since it is larger than the sum of its proper divisors (563421328024).

643550243576 is a wasteful number, since it uses less digits than its factorization.

643550243576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20990998 (or 20990994 counting only the distinct ones).

The product of its (nonzero) digits is 9072000, while the sum is 50.

The spelling of 643550243576 in words is "six hundred forty-three billion, five hundred fifty million, two hundred forty-three thousand, five hundred seventy-six".