643703642 has 8 divisors (see below), whose sum is σ = 974414100. Its totient is φ = 318898944.

The previous prime is 643703617. The next prime is 643703647. The reversal of 643703642 is 246307346.

643703642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 620557921 + 23145721 = 24911^2 + 4811^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (643703647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1476167 + ... + 1476602.

Almost surely, 2^643703642 is an apocalyptic number.

643703642 is a deficient number, since it is larger than the sum of its proper divisors (330710458).

643703642 is a wasteful number, since it uses less digits than its factorization.

643703642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2952880.

The product of its (nonzero) digits is 72576, while the sum is 35.

The square root of 643703642 is about 25371.3153383895. The cubic root of 643703642 is about 863.4330244031.

The spelling of 643703642 in words is "six hundred forty-three million, seven hundred three thousand, six hundred forty-two".