643732 has 6 divisors (see below), whose sum is σ = 1126538. Its totient is φ = 321864.

The previous prime is 643729. The next prime is 643751. The reversal of 643732 is 237346.

It can be written as a sum of positive squares in only one way, i.e., 538756 + 104976 = 734^2 + 324^2 .

It is a junction number, because it is equal to n+sod(n) for n = 643697 and 643706.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80463 + ... + 80470.

2⁶⁴³⁷³² is an apocalyptic number.

It is an amenable number.

643732 is a deficient number, since it is larger than the sum of its proper divisors (482806).

643732 is a wasteful number, since it uses less digits than its factorization.

643732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160937 (or 160935 counting only the distinct ones).

The product of its digits is 3024, while the sum is 25.

The square root of 643732 is about 802.3291095305. The cubic root of 643732 is about 86.3445703568.

The spelling of 643732 in words is "six hundred forty-three thousand, seven hundred thirty-two".