643685104 has 20 divisors (see below), whose sum is σ = 1248823840. Its totient is φ = 321408000.

The previous prime is 643685099. The next prime is 643685167. The reversal of 643685104 is 401586346.

It is a happy number.

It is a super-2 number, since 2×643685104² = 828661026222981632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14769 + ... + 38800.

It is an arithmetic number, because the mean of its divisors is an integer number (62441192).

Almost surely, 2^643685104 is an apocalyptic number.

It is an amenable number.

643685104 is a deficient number, since it is larger than the sum of its proper divisors (605138736).

643685104 is a wasteful number, since it uses less digits than its factorization.

643685104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54328 (or 54322 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 643685104 is about 25370.9500019215. The cubic root of 643685104 is about 863.4247356638.

The spelling of 643685104 in words is "six hundred forty-three million, six hundred eighty-five thousand, one hundred four".