643718568315672 has 160 divisors (see below), whose sum is σ = 1909348579155600. Its totient is φ = 201921170651136.

The previous prime is 643718568315569. The next prime is 643718568315727. The reversal of 643718568315672 is 276513865817346.

643718568315672 is a `hidden beast` number, since 6 + 4 + 3 + 7 + 1 + 8 + 56 + 8 + 3 + 1 + 567 + 2 = 666.

It is a super-3 number, since 3×643718568315672³ (a number of 45 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 643718568315672.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 70530579 + ... + 79132797.

Almost surely, 2^{643718568315672} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643718568315672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (954674289577800).

643718568315672 is an abundant number, since it is smaller than the sum of its proper divisors (1265630010839928).

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

643718568315672 is a wasteful number, since it uses less digits than its factorization.

643718568315672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8609047 (or 8609034 counting only the distinct ones).

The product of its digits is 1219276800, while the sum is 72.

The spelling of 643718568315672 in words is "six hundred forty-three trillion, seven hundred eighteen billion, five hundred sixty-eight million, three hundred fifteen thousand, six hundred seventy-two".