643745856004 has 12 divisors (see below), whose sum is σ = 1129898144284. Its totient is φ = 320917814784.

The previous prime is 643745855971. The next prime is 643745856041. The reversal of 643745856004 is 400658547346.

It can be written as a sum of positive squares in 2 ways, for example, as 97033496004 + 546712360000 = 311502^2 + 739400^2 .

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, 238776789 + ... + 238779484.

Almost surely, 2^643745856004 is an apocalyptic number.

It is an amenable number.

643745856004 is a deficient number, since it is larger than the sum of its proper divisors (486152288280).

643745856004 is a wasteful number, since it uses less digits than its factorization.

643745856004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477556614 (or 477556612 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 52.

The spelling of 643745856004 in words is "six hundred forty-three billion, seven hundred forty-five million, eight hundred fifty-six thousand, four".