643048913 has 4 divisors (see below), whose sum is σ = 692514228. Its totient is φ = 593583600.

The previous prime is 643048907. The next prime is 643048963. The reversal of 643048913 is 319840346.

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 200703889 + 442345024 = 14167^2 + 21032^2 .

It is a cyclic number.

It is not a de Polignac number, because 643048913 - 2⁸ = 643048657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643048963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24732638 + ... + 24732663.

It is an arithmetic number, because the mean of its divisors is an integer number (173128557).

Almost surely, 2^643048913 is an apocalyptic number.

It is an amenable number.

643048913 is a deficient number, since it is larger than the sum of its proper divisors (49465315).

643048913 is a wasteful number, since it uses less digits than its factorization.

643048913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49465314.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 643048913 is about 25358.4091180815. The cubic root of 643048913 is about 863.1401844594.

The spelling of 643048913 in words is "six hundred forty-three million, forty-eight thousand, nine hundred thirteen".