643534201 has 16 divisors (see below), whose sum is σ = 702129168. Its totient is φ = 587520000.

The previous prime is 643534193. The next prime is 643534217. The reversal of 643534201 is 102435346.

It can be written as a sum of positive squares in 8 ways, for example, as 82791801 + 560742400 = 9099^2 + 23680^2 .

It is not a de Polignac number, because 643534201 - 2³ = 643534193 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643534201.

It is not an unprimeable number, because it can be changed into a prime (643534231) 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, 71451 + ... + 79951.

It is an arithmetic number, because the mean of its divisors is an integer number (43883073).

Almost surely, 2^643534201 is an apocalyptic number.

643534201 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

643534201 is a deficient number, since it is larger than the sum of its proper divisors (58594967).

643534201 is a wasteful number, since it uses less digits than its factorization.

643534201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8652.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 643534201 is about 25367.9758948167. The cubic root of 643534201 is about 863.3572577592.

Adding to 643534201 its reverse (102435346), we get a palindrome (745969547).

The spelling of 643534201 in words is "six hundred forty-three million, five hundred thirty-four thousand, two hundred one".