643472 has 20 divisors (see below), whose sum is σ = 1260336. Its totient is φ = 318240.

The previous prime is 643469. The next prime is 643493. The reversal of 643472 is 274346.

It is a happy 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, 1943 + ... + 2249.

2⁶⁴³⁴⁷² is an apocalyptic number.

It is an amenable number.

643472 is a deficient number, since it is larger than the sum of its proper divisors (616864).

643472 is a wasteful number, since it uses less digits than its factorization.

643472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 440 counting only the distinct ones).

The product of its digits is 4032, while the sum is 26.

The square root of 643472 is about 802.1670648936. The cubic root of 643472 is about 86.3329440841.

The spelling of 643472 in words is "six hundred forty-three thousand, four hundred seventy-two".