643264401 has 16 divisors (see below), whose sum is σ = 924416640. Its totient is φ = 395531520.

The previous prime is 643264381. The next prime is 643264403. The reversal of 643264401 is 104462346.

It is not a de Polignac number, because 643264401 - 2⁹ = 643263889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643264403) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 47020 + ... + 59138.

It is an arithmetic number, because the mean of its divisors is an integer number (57776040).

Almost surely, 2^643264401 is an apocalyptic number.

It is an amenable number.

643264401 is a deficient number, since it is larger than the sum of its proper divisors (281152239).

643264401 is a wasteful number, since it uses less digits than its factorization.

643264401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13496.

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 643264401 is about 25362.6576091702. The cubic root of 643264401 is about 863.2365874837.

The spelling of 643264401 in words is "six hundred forty-three million, two hundred sixty-four thousand, four hundred one".