643037545 has 4 divisors (see below), whose sum is σ = 771645060. Its totient is φ = 514430032.

The previous prime is 643037533. The next prime is 643037567. The reversal of 643037545 is 545730346.

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

It can be written as a sum of positive squares in 2 ways, for example, as 116380944 + 526656601 = 10788^2 + 22949^2 .

It is a cyclic number.

It is not a de Polignac number, because 643037545 - 2⁵ = 643037513 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64303750 + ... + 64303759.

It is an arithmetic number, because the mean of its divisors is an integer number (192911265).

Almost surely, 2^643037545 is an apocalyptic number.

It is an amenable number.

643037545 is a deficient number, since it is larger than the sum of its proper divisors (128607515).

643037545 is a wasteful number, since it uses less digits than its factorization.

643037545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128607514.

The product of its (nonzero) digits is 151200, while the sum is 37.

The square root of 643037545 is about 25358.1849705376. The cubic root of 643037545 is about 863.1350981510.

The spelling of 643037545 in words is "six hundred forty-three million, thirty-seven thousand, five hundred forty-five".