643501672 has 32 divisors (see below), whose sum is σ = 1338573600. Its totient is φ = 287540800.

The previous prime is 643501657. The next prime is 643501687. The reversal of 643501672 is 276105346.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (643501657) and next prime (643501687).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56779 + ... + 67162.

It is an arithmetic number, because the mean of its divisors is an integer number (41830425).

Almost surely, 2^643501672 is an apocalyptic number.

It is an amenable number.

643501672 is an abundant number, since it is smaller than the sum of its proper divisors (695071928).

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

643501672 is a wasteful number, since it uses less digits than its factorization.

643501672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124017 (or 124013 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 643501672 is about 25367.3347437211. The cubic root of 643501672 is about 863.3427106839.

The spelling of 643501672 in words is "six hundred forty-three million, five hundred one thousand, six hundred seventy-two".