643505602 has 4 divisors (see below), whose sum is σ = 965258406. Its totient is φ = 321752800.

The previous prime is 643505593. The next prime is 643505617. The reversal of 643505602 is 206505346.

643505602 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 346667161 + 296838441 = 18619^2 + 17229^2 .

It is a super-4 number, since 4×643505602⁴ (a number of 36 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160876399 + ... + 160876402.

Almost surely, 2^643505602 is an apocalyptic number.

643505602 is a deficient number, since it is larger than the sum of its proper divisors (321752804).

643505602 is a wasteful number, since it uses less digits than its factorization.

643505602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321752803.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 643505602 is about 25367.4122054261. The cubic root of 643505602 is about 863.3444682188.

The spelling of 643505602 in words is "six hundred forty-three million, five hundred five thousand, six hundred two".