643974401368 has 16 divisors (see below), whose sum is σ = 1259949916080. Its totient is φ = 307987757088.

The previous prime is 643974401353. The next prime is 643974401377. The reversal of 643974401368 is 863104479346.

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, 1749930255 + ... + 1749930622.

It is an arithmetic number, because the mean of its divisors is an integer number (78746869755).

Almost surely, 2^643974401368 is an apocalyptic number.

It is an amenable number.

643974401368 is a deficient number, since it is larger than the sum of its proper divisors (615975514712).

643974401368 is a wasteful number, since it uses less digits than its factorization.

643974401368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3499860906 (or 3499860902 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 55.

The spelling of 643974401368 in words is "six hundred forty-three billion, nine hundred seventy-four million, four hundred one thousand, three hundred sixty-eight".