643442829 has 4 divisors (see below), whose sum is σ = 857923776. Its totient is φ = 428961884.

The previous prime is 643442827. The next prime is 643442837. The reversal of 643442829 is 928244346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643442829 - 2¹ = 643442827 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643442827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107240469 + ... + 107240474.

It is an arithmetic number, because the mean of its divisors is an integer number (214480944).

Almost surely, 2^643442829 is an apocalyptic number.

It is an amenable number.

643442829 is a deficient number, since it is larger than the sum of its proper divisors (214480947).

643442829 is a wasteful number, since it uses less digits than its factorization.

643442829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214480946.

The product of its digits is 331776, while the sum is 42.

The square root of 643442829 is about 25366.1748988688. The cubic root of 643442829 is about 863.3163946561.

The spelling of 643442829 in words is "six hundred forty-three million, four hundred forty-two thousand, eight hundred twenty-nine".