643408433 has 8 divisors (see below), whose sum is σ = 651667776. Its totient is φ = 635202000.

The previous prime is 643408421. The next prime is 643408453. The reversal of 643408433 is 334804346.

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

It is a cyclic number.

It is not a de Polignac number, because 643408433 - 2¹² = 643404337 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643408393 and 643408402.

It is not an unprimeable number, because it can be changed into a prime (643408453) 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 7 ways as a sum of consecutive naturals, for example, 11543 + ... + 37683.

It is an arithmetic number, because the mean of its divisors is an integer number (81458472).

Almost surely, 2^643408433 is an apocalyptic number.

It is an amenable number.

643408433 is a deficient number, since it is larger than the sum of its proper divisors (8259343).

643408433 is a wasteful number, since it uses less digits than its factorization.

643408433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26455.

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

The square root of 643408433 is about 25365.4969003172. The cubic root of 643408433 is about 863.3010111812.

The spelling of 643408433 in words is "six hundred forty-three million, four hundred eight thousand, four hundred thirty-three".