643634824207 has 4 divisors (see below), whose sum is σ = 665829128520. Its totient is φ = 621440519896.

The previous prime is 643634824201. The next prime is 643634824229. The reversal of 643634824207 is 702428436346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643634824207 - 2³ = 643634824199 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643634824201) 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 3 ways as a sum of consecutive naturals, for example, 11097152113 + ... + 11097152170.

It is an arithmetic number, because the mean of its divisors is an integer number (166457282130).

Almost surely, 2^643634824207 is an apocalyptic number.

643634824207 is a deficient number, since it is larger than the sum of its proper divisors (22194304313).

643634824207 is a wasteful number, since it uses less digits than its factorization.

643634824207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22194304312.

The product of its (nonzero) digits is 4644864, while the sum is 49.

The spelling of 643634824207 in words is "six hundred forty-three billion, six hundred thirty-four million, eight hundred twenty-four thousand, two hundred seven".