643403499 has 4 divisors (see below), whose sum is σ = 857871336. Its totient is φ = 428935664.

The previous prime is 643403477. The next prime is 643403533. The reversal of 643403499 is 994304346.

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 643403499 - 2¹⁵ = 643370731 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643403499.

It is not an unprimeable number, because it can be changed into a prime (643403429) 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, 107233914 + ... + 107233919.

It is an arithmetic number, because the mean of its divisors is an integer number (214467834).

Almost surely, 2^643403499 is an apocalyptic number.

643403499 is a deficient number, since it is larger than the sum of its proper divisors (214467837).

643403499 is a wasteful number, since it uses less digits than its factorization.

643403499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214467836.

The product of its (nonzero) digits is 279936, while the sum is 42.

The square root of 643403499 is about 25365.3996420321. The cubic root of 643403499 is about 863.2988044243.

The spelling of 643403499 in words is "six hundred forty-three million, four hundred three thousand, four hundred ninety-nine".