643443018201 has 27 divisors (see below), whose sum is σ = 949780229151. Its totient is φ = 419761363104.

The previous prime is 643443018143. The next prime is 643443018299. The reversal of 643443018201 is 102810344346.

The square root of 643443018201 is 802149.

It is a perfect power (a square), and thus also a powerful number.

643443018201 is a `hidden beast` number, since 6 + 4 + 3 + 4 + 430 + 18 + 201 = 666.

It can be written as a sum of positive squares in only one way, i.e., 614814378201 + 28628640000 = 784101^2 + 169200^2 .

It is not a de Polignac number, because 643443018201 - 2¹³ = 643443010009 is a prime.

It is a super-2 number, since 2×643443018201² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (643443019201) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 113100165 + ... + 113105853.

Almost surely, 2^643443018201 is an apocalyptic number.

643443018201 is the 802149-th square number.

643443018201 is the 401075-th centered octagonal number.

It is an amenable number.

643443018201 is a deficient number, since it is larger than the sum of its proper divisors (306337210950).

643443018201 is an frugal number, since it uses more digits than its factorization.

643443018201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11478 (or 5739 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

Multiplying 643443018201 by its sum of digits (36), we get a square (23163948655236 = 4812894²).

The spelling of 643443018201 in words is "six hundred forty-three billion, four hundred forty-three million, eighteen thousand, two hundred one".