643342823 has 8 divisors (see below), whose sum is σ = 659586048. Its totient is φ = 627157944.

The previous prime is 643342811. The next prime is 643342837. The reversal of 643342823 is 328243346.

It is a happy number.

643342823 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643342823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643302823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8186 + ... + 36792.

It is an arithmetic number, because the mean of its divisors is an integer number (82448256).

Almost surely, 2^643342823 is an apocalyptic number.

643342823 is a deficient number, since it is larger than the sum of its proper divisors (16243225).

643342823 is a wasteful number, since it uses less digits than its factorization.

643342823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29173.

The product of its digits is 82944, while the sum is 35.

The square root of 643342823 is about 25364.2035751174. The cubic root of 643342823 is about 863.2716658479.

The spelling of 643342823 in words is "six hundred forty-three million, three hundred forty-two thousand, eight hundred twenty-three".