643927011 has 24 divisors (see below), whose sum is σ = 1062512640. Its totient is φ = 339651936.

The previous prime is 643927001. The next prime is 643927013. The reversal of 643927011 is 110729346.

643927011 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643927011 - 2¹⁷ = 643795939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643927013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87171 + ... + 94268.

It is an arithmetic number, because the mean of its divisors is an integer number (44271360).

Almost surely, 2^643927011 is an apocalyptic number.

643927011 is a deficient number, since it is larger than the sum of its proper divisors (418585629).

643927011 is a wasteful number, since it uses less digits than its factorization.

643927011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181475 (or 181462 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 643927011 is about 25375.7169553887. The cubic root of 643927011 is about 863.5328849883.

The spelling of 643927011 in words is "six hundred forty-three million, nine hundred twenty-seven thousand, eleven".